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ADVANCES IN CARDIOVASCULAR RESEARCH From genes and molecules to clinical applications International symposium September 27 - 29, 2008 Hotel Hradná Brána Devín-Bratislava, Slovakia P P r r o o g g r r a a m m & B B o o o o k k o o f f A A b b s s t t r r a a c c t t s s Edited by Táňa Ravingerová VEDA Publishing House of the Slovak Academy of Sciences September 2008, Bratislava, Slovak Republic

Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

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Page 1: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

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Page 2: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

Welcome address Dear Colleagues and Friends,

It is my great pleasure to invite you to attend the international symposium “Advances in

Cardiovascular Research: From genes and molecules to clinical applications”, which will

be held at Devín – Bratislava, Slovakia in the Hotel Hradná Brána (Castle Gate) close to the

ruins of Devin Castle.

The goal of the Symposium is to bring together renowned scientists; clinicians, physiologists,

morphologists, molecular cardiologists, geneticists and all those working in the field of

cardiovascular research, the field, which has become so important, challenging and

rewarding.

The programme of the Symposium includes keynote lectures on selected topics, free oral

communications and poster presentations. We promise to create an exciting, enjoyable and

friendly atmosphere, which will be multiplied by your participation.

The Symposium will provide an excellent opportunity for an exchange of experience and new

ideas and will contribute to our understanding of the complexity of signaling pathways and

processes leading to the heart hypertrophy and failure, to its adaptation to ischemia, hypoxia,

overload and related pathophysiological situations, as well as for presentation of some novel

approaches towards the management of cardiovascular diseases.

We hope that despite heavy scientific schedule, there will be enough space for fruitful and

stimulating discussions and chances to enjoy the beautiful natural environment and important

historical place at the confluence of the Danube and Moravia rivers.

We are looking forward to your participation in this meeting.

Jan Slezak

On behalf of the Organizing Committee

2

Page 3: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

Organization and committees

Symposium is organized by

Institute for Heart Research SAS CEKVY SAS Slovak Academy of Sciences

Slovak Society of Cardiology Slovak League Heart to Heart

Slovak Physiological Society

Institute of Cardiovascular Scien Academy of Sciences and Arts

Under the au f the International Academy of Cardiovascular Sciences

OCAL ORGANIZING OMMITTEE

Jan Slezak (president of the meeting), Jan Styk (vice-president of the meeting), Tana Ravingerova (scientific secretary), Attila Ziegelhoffer, Narcis Tribulova, Jan Murin, Eva Goncalvesova, Andrej Dukat, Gabriel Kamensky, Valentin Both, Ludmila Okruhlicova, Monika Bartekova, Miroslav Ferko, Katarina Dlugosova, Jana Matejikova, Jana Mujkosova, Maria Zazrivcova

INTERNATIONAL ADVISORY BOARD Naranjan S. Dhalla, Lorrie Kirshenbaum, Grant N. Pierce, Dennis B. McNamara, Pawan K. Singal, Felix Unger CONTACTS Institute for Heart Research SAS Dúbravská cesta 9, P.O.B. 104, 840 05 Bratislava 45 Phone: 00421 2 54774405 Fax: 00421 2 54776637 E-mail: [email protected]; [email protected]

ces European

spices o

LC

3

Page 4: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

General information

lovanske nabrezie 15, 84110 Bratislava – Dev

, S ntis Pharma Slovakia s. r. o., Roche .r.o., FISHER Slovakia, s.r.o.

EGISTRATION Congress materials and badges will be available at the registration desk:

September 28th 8.00 – 18.00 29th 8.00 – 12.30

ion to the Devin Castle er and Get together party

NSTRUCTION FOR PRESENTERS

e lecture hall. osters will be displayed on September 28th throughout the whole day. Authors should be

rs during the guided Poster session.

PROGRAM O

aturday, September 27th commodation

Sunday, Septeion II.

Lunch tle

Session III. Session IV.

Session VI. Closing Lunch/Farewell

SYMPOSIUM VENUE Hotel Hradná Brána (Castle Gate) S ín, Slovakia Phone: 00421-2-601 025 11 Fax: 00421-2-601 025 12 E-mail: [email protected] SPONSORS Bayer HealthCare, Bayer Schering PharmaSlovensko, s

anofi-Ave

R

September 27th 18.00 – 20.00

September SOCIAL PROGRAM Sunday, September 28th

Guided excursReception dinn

I Audio-visual equipment will be provided for PowerPoint presentations. Please, handle your presentation in advance to the attendant in thPpresent at their postePosters size: 85 cm width, 110 cm length.

VERVIEW

SArrival, ac

mber 28th Session I. Sess

Excursion to the Devin cas

Poster Session Reception dinner and Get together party

Monday, September 29th

Session V.

4

Page 5: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

Scientific Programme

PTEMBER 27TH

and accommodation SATURDAY, SE

19.00. – 20.00 Arrival DAY, SEPTEMBER 28 SUNTH

8.45

Opening: Jan Slezak, Naranjan S. Dhalla

9.00 – 10.40 Session I. Diabetes, dyslipidemia, metabolic syndrom - from basic knowled

ge to the prospective pharmacological approaches

urin (Slovakia), Grant Pierce (Canada)

Rescue of diabetes related impairment of myocardial angiogenesis by gene

nada) he effect of trans fats on cardiovascular health

A) Insulin glargine, but not insulin glulisine, attenuates catheter-induced carotid

f IGF-1

of e metabolic syndrome

0.20 - 10.40 ana Ravingerova, Bratislava (Slovakia) o ed in yocardial response

Chairs: Jan M

9.00 - 9.20 Nilanjana Maulik, Farmington (USA)

therapy: potential and challenges 9.20 - 9.40 Grant Pierce, Winnipeg (Ca

T

0 - 10.00 Dennis B. McNamara, New Orleans (US9.4

intimal hyperplasia in Zucker fatty rats: Role o 10.00 - 10.20 Stephen W. Schaffer, Mobile (USA)

Contributions of lipids and diabetes in ischemic injury in a rat modelth

1 T

Changes in PPAR gene expression are inv lv mto ischemic injury in normal and diseased heart: relevance to pleiotropic effects of statins

10.40 – 11.10

Coffee break

11.10 – 12.30 Session II. Sympathetic nervous system and RAAS - known or yet unknown?

en (Canada)

ects

ical activities of heart

Chairs: Olga Pechanova (Slovakia), Frans H.H. Leen

11.10 - 11.30 Belma Turan, Ankara (Turkey)

Chronic treatments with beta-adrenergic blockers have differential effon electrical and mechan

11.30 - 11.50 Frans H.H. Leenen, Ottawa (Canada)

Brain mechanism contributing to sympathetic hyperactivity and heart

5

Page 6: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

failure. Critical role for tissue RAAS

1.50 - 12.10 rivastava, Montreal (Canada) induced Gi signaling in hypertension

r Research Topics in the Health Priority Area 3rd Call of the th ent

13.40 - 15.40

adhu Anand-S1 M

Angiotensin II-

Let us work together - Networking Valentin Both, Bratislava (Slovakia) Cardiovascula

12.10 - 12.30

EU 7 Framework Programme for Research and Technology Developm

12.30 - 13.40 Lunch

Guided excursion to the Devin Castle

15.40 - 17.15 Session III. NO and cardiovascular protection kia), Andrzej Beresewicz (Poland)

ar mechanisms of vasculoprotective effect of NO

arrhythmias

ffect of Provinol on cardiac Na ,K -ATPase during hypertension

offee break

Chairs: Ludmila Okruhlicova (Slova 15.40 - 16.00 Philip J. Kadowitz, New Orleans (USA)

Nitrite therapy for CV disease 16.00 - 16.20 Olga Pechanova, Bratislava (Slovakia)

Peripheral and central regulation of blood pressure: the role of nitric oxide Ashok Srivastava, Montreal (Canada) 16.20 - 16.40Molecul

16.40 - 17.00 Agnes Vegh, Szeged (Hungary)

eroxynitrite-induced protection against P

17.00 - 17.15 Norbert Vrbjar, Bratislava (Slovakia) + +E

17.15 - 17.30 C 17.30 - 19.05 Session IV. Adaptative (protective?) mechanisms in

cardiovascular system

hairs: Tana Ravingerova (Slovakia), Agnes Vegh (Hungary) C

17.30 - 17.50 Michael P. Czubryt, Winnipeg (Canada)

he transcription factor scleraxis is a novel regulator of cardiac collagen Tsynthesis

arie Novakova, Brno (Czech Republic) 17.50 - 18.05

eptors in rat and mouse under

ttila Ziegelhoffer, Bratislava (Slovakia) rbonic anhydrase IX in hypoxic rat cardiomyocytes: role of

MExpression of the cardiac sigma recphysiological and various pathological conditions A18.05 - 18.20Induction of ca

6

Page 7: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

the mitochondria

18.20 - 18.35 ava (Slovakia) protein, connexin-43, a key player or

y?

8.50 - 19.05 kruhlicova, Bratislava (Slovakia) orta of rats with different

Narcis Tribulova, Bratisl

myocardial gap junction channel Isbystander in modulation of cardiac lethal arrhythmia susceptibilit

18.35 - 18.50 Amarjit S. Arneja, Winnipeg (Canada)

How perıpheral arterial disease may predict coronary artery events

udmila O1 LVariability of connexin-43 expression in the agenotype

19.05 - 20.00 Poster Session - guided

Chairs: Narcis Tr ibulova (Slovakia), Zoltan Papp (Hungary) - Part I. arie Novakova (Czech Republic), Grant Pierce (Canada) – Part II.

20.00 - 23.00

M

Reception dinner and Get together party

TH

MONDAY, SEPTEMBER 29

9.00 – 10.50 Session V. New aspects of heart failure

9.00 - 9.20 awan K. Singal, Winnipeg (Canada) ) imbalance in heart failure

.20 - 9.40

ngestive heart failure

o be On TARGET - aimed on better cardiovascular prevention:

0 lvesova, Bratislava (Slovakia)

5

Chairs: Jan Styk (Slovakia), Pawan K. Singal (Canada)

PCytokine (TNF-α and IL-10

9 Jan Murin, Gabriel Kamensky, Bratislava (Slovakia)

Renal dysfunction and heart failure 9.40 - 10.00 Naranjan S. Dhalla, Winnipeg (Canada)

echanisms of subcellular remodeling in coM

10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure

10.20 - 10.35 Andrej Dukat, Bratislava (Slovakia)

TONTARGET results

10.35 - 10.5 Milan Luknar, Peter Lesny, Eva Gonca

BNP in acute heart failure 10.50 - 11.0 Coffee break

7

Page 8: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

11.05 - 12.30: Session VI. Mechanisms of cell death and survival

hairs: Attila Ziegelhoffer (Slovakia), Naranjan S. Dhalla (Canada)

11.05 - 11.25 ypoxia-induced disruption of Rb/E2F-1 inhibitory complexes provokes

tricular myocytes 11.25 - 11.45 Warsaw (Poland)

ost-ischemic endothelial injury and its protection by ischemic

1.45 - 12.05 ipak K. Das, Farmington (USA)

ptation and autophagy - a cry for survival

diac myocytes to hronic ischemia and return to functional myocardium

losing remarks: Jan Slezak, Pawan K. Singal

12.30

C

Lorrie A. Kirshenbaum, Winnipeg (Canada) HBnip3 gene expression and cell death of ven Andrzej Beresewicz,Ppreconditioning

1 DMyocardial ada

12.05 - 12.20 Jan Slezak, Bratislava (Slovakia)

Hibernating myocardium: Adaptation remodeling of carc

C

Lunch / Farewell

8

Page 9: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

Poster Session

ist of Poster presentations

art I.

1. Barbara Bacova, Katarina Dlugosova1, Miroslav Barancik1, Ludmila Okruhlicova1, Narcis Tribulova1, Bratislava (Slovakia) Omega-3 fatty acids attenuate down-regulation of myocardial connexin-43 in spontaneously hypertensive and hereditary hypetriglyceridemic rats

2. Monika Bartekova1, Dezider Pancza1, Olga Krizanova2, Albert Breier2, Jan Styk1, Tana Ravingerova1, Bratislava (Slovakia) The effect of quercetin on ischemia/reperfusion injury in isolated rat heart

3. Katarina Dlugosova1, Marcela Mitasíkova1, Ruzena Sotnikova2, Iveta Bernatova3, Peter

Weismann4, Narcisa Tribulova1, Jan Slezak1, Ludmila Okruhlicova1, Bratislava (Slovakia) 3-omega polyunsaturated fatty acids-treatment increases connexin43 expression in aorta of aged SHR

4. Miroslav Ferko1, Jana Mujkosová1, Tereza Holotnakova2, Dana Kincelova3, Iveta Waczulíkova3, Olga Pechanova4, Olga Ulicna5, Tana Ravingerova1, Attila Ziegelhöffer1, Bratislava (Slovakia) Endogenous protective mechanisms in acute diabetic rat heart: Different involvement of free radicals

5. Eva Goncalvesova1, Jan Lakota2, Viliam Fridrich1, Pavol Povinec3, Milan Luknar1, Juraj

Fabian1, Bratislava (Slovakia) Feasibility and safety of intracoronary injection of mesenchymal stem cells in severe ischemic cardiomyopathy. Immediate, intermediate, and long-term follow-up

6. Veronika Javorkova1, Jana Vlkovicova1, Lucia Mezesova1, Olga Pechanova2, Norbert

Vrbjar1, Bratislava (Slovakia) Sexual dimorphism in functional properties of cardiac Na,K-ATPase in SHR

Part II. 7. Lucia Kolenova, Katarina Dlugosova1, Vladimir Knezl2, Peter Weismann3, Ludmila

Okruhlicova1, Jan Jakubovsky, Narcis Tribulova1, Bratislava (Slovakia) Atorvastatin and omega-3 fatty acids decrease susceptbility of hypertriglyceridemic rat heart to lethal arrhythmias. Connexin-43 implication

8. Vladimir Knezl, Jan Drimal, Marcela Mitasikova1, Peter Weismann2, Narcis Tribulova1,

Bratislava (Slovakia) Sex differences in the incidence of lethal arrhythmias correlate with myocardial connexin-43 expression disparaties

L P

Page 10: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

9. Jana Matejikova1, Jarmila Kuchar 2 3 Frantisek Kolar3, Dezider Pancza1, Tana Ravingerova1, Bratislava (SlProtection against ischemia-induced arrhythmias in the diabetic heart does not require

signaling: relevance to ischemic preconditioning

a Mujkosova1, Michal Cagalinec2, Miroslav Ferko1, Olga Ulicna3, Iveta aczulikova2, Dana Kincelova2, Tana Ravingerova1, Attila Ziegelhőffer1, Bratislava

11. rnatova, Bratislava

1 1 1 2

13.

ska , Jan Neckar , ovakia)

PI3K/Akt activation and ROS 10. Jan

W(Slovakia) Calcium signaling to rat heart mitochondria in acute diabetes: a measure for salvage of cardiac energetics

ozef Torok, Angelika Puzserova, Anna Zemancikova, Iveta BeJ(Slovakia) Effect of chronıc socıal stress on blood pressure and neurogenıc contractıons of mesenterıc artery ın rats wıth genetıc hypertensıon

12. Jana Vlkovicova , Veronika Javorkova , Lucia Mezesova , Olga Pechanova , Norbert Vrbjar1, Bratislava (Slovakia) Regularion of cardiac Na,K-ATPase by nitric oxide during hypertension Maria Zazrivcova1, Adriana Adameova2, Dezider Pancza1, Ján Styk1, Tana

avingerova1, Bratislava (Slovakia) RProtective effects of treatment with simvastatin against ischemia/ reperfusion injury in isolated rat heart

10

Page 11: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

ABSTRACTS OF ORAL COMMUNICATIONS Session I. Diabetes, dyslipidemia, metabolic syndrom - from basic knowledge to t he p

rospective pharmacological approaches

11

Page 12: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

RESCUE OF DIABETES RELATED IMPAIRMENT OF MYOCARDIAL NGIOGENESIS BY GENE THERAPY: POTENTIAL AND CHALLENGES

ry, Department of Surgery, University of onnecticut Medical School, Farmington, Connecticut-06030, USA

he last few decades have seen significant advancement in the knowledge of the molecular

echanism of angiogenesis and how it can be modulated to treat pathological conditions such

s cancer and ischemic heart diseases. When an oncologist is interested to inhibit

ngiogenesis and thereby curb tumor growth and metastasis, a cardiologist would aim at

ducing angiogenesis to rejuvenate the failing heart. Therapeutic angiogenesis makes use of

e angiogenic potential of a drug or growth factor (protein or gene) to promote the

evelopment of endogenous collateral vessels in the ischemic myocardium. However, therapy

sing recombinant vectors encoding a single angiogenic growth factor (Vascular Endothelial

rowth Factor/VEGF and Angiopoietin-1/Ang1) has shown less significant improvement

an what was expected, mainly because the biological system requires a cascade of growth

ctors, their receptors, and responsive intracellular signaling mechanisms for the

evelopment of a fully functional vascular system. Therefore, therapeutic angiogenesis is

urrently targeting combinations of angiogenic molecules as a measure to induce myocardial

ngiogenesis. A strategy to locally overexpress VEGF and Ang-1 in combination would prove

be beneficial because while VEGF can take the lead in the process of neovascualrization,

ng-1 would be expected to support the maturation of the newly formed vessels. A number of

tudies in rabbit, rat and mice models of hind limb or myocardial ischemia, have

emonstrated the efficacy of coexpressing VEGF and Ang-1 in inducing revascularization

nd improving vascular perfusion when compared to overexpressing either one of these

rowth factors. However, pathological conditions such diabetes reflects a far more

hallenging condition, where the angiogenic system (VEGF and Ang1) is significantly

ownregulated thereby hampering the hearts ability to respond to an ischemic stress.

herefore supporting the overexpression of these angiogenic factors by means of gene therapy

ould be expected to correct the process of impaired angiogenesis in the diabetic ischemic

yocardium. These astounding possibilities paved the way for the induction of angiogenesis

y intramyocardial co-administration of adenovirus encoding VEGF and Ang1 in the diabetic

chemic heart. Our results have documented that intramyocardial administration of vectors

ncoding VEGF and Ang1 in combination significantly reduced infarct size and myocardial

brosis in the diabetic ischemic heart when compared to the Ad-LacZ treated diabetic control.

A Nilanjana Maulik

olecular Angiogenesis and Cardiology LaboratoMC T

m

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in

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fi

12

Page 13: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

THE EFFECT OF TRANS FATS ON CARDIOVASCULAR HEALTH Grant N. Pierce, Chantal M.C. Dupasquier, Andrea L. Edel, David Blackwood, Thane

lanie N. Richard and Elena Dibrov.

University of Manitoba, innipeg, Canada

G. Maddaford, MeCanadian Centre for Agri-food Research in Health and Medicine, St Boniface Hospital Research Centre, Department of Physiology, Faculty of Medicine,W Epidemiological studies have shown that ingestion of trans fatty acids in the diet are

associated with a high incidence of cardiovascular disease. Because of this, many countries

have legislated against the inclusion of trans fats in foods. This legislation and the data on the

deleterious effects of trans fats have important implications for a variety of dietary areas

including the dairy industry. Many dairy products naturally contain significant quantities of

trans fats and it is possible that the deleterious effects of trans fats may have a large

detrimental impact upon the dairy industry as a whole. It is surprising, therefore, in view of

these data and such governmental intervention, that the mechanism whereby trans fats

generate cardiovascular complications has not been identified. It has been assumed that trans

fats contribute to atherogenesis but the few studies that have tested this hypothesis have

produced negative results. As well, it is possible that the trans fat found in dairy products

(vaccenic acid) may have different effects on the cardiovascular system than the hydrogenated

trans fat primarily ingested (elaidic acid). The talk will present our latest data demonstrating

that dietary trans fat will, under selected conditions, induce atherosclerosis in an excellent

animal model of coronary heart disease. We will also discuss our recent findings that dietary

supplementation with the trans fats elaidic acid and vaccenic acid will produce very different

effects on atherogenesis. Our data provide mechanistic information on the cardiovascular

action of trans fats and this has an impact upon not only our health but the food industry as

well.

13

Page 14: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

INSULIN GLARGINE REDUCES CAROTID INTIMAL HYPERPLASIA AFTER ALLOON CATHETER INJURY IN ZUCKER FATTY RATS POSSIBLY BY IGF-1

ealth Sciences Center, New Orleans, LA 70112

lloon catheter injury in obese non diabetic animals. These

nd are associated with an increase in serum

ular oxidative stress.

BMEDIATED REDUCTION IN OXIDATIVE STRESS Dennis B. McNamara, Subramanyam N. Murthy, Philip J. Kadowitz and Vivian Fonseca Tulane University H

OBJECTIVE: To test the effect of short acting (glulisine) and long acting (glargine) insulin

on vascular intimal hyperplasia in the carotid artery following balloon catheter injury in

Zucker fatty rat.

RESEARCH DESIGN AND METHODS: Non diabetic Zucker fatty rats were injected 0.45

mg/kg of glargine (once) or glulisine (twice) daily for 1 week before and 3 weeks after

balloon injury and then sacrificed. Sections of the carotid artery were used for measuring

intima/media ratio, in a blinded manner. Sections were stained for nitrotyrosine and 8-

isoprostane was assayed in the aortic arch protein. Glucose and IGF-1 were measured in

blood.

RESULTS–: Compared to controls carotid intima/media ratio was significantly reduced only

in the glargine treated animals [0. 9 ± 0.1-control; 0.6 ± 0.1-glulisine; 0.4 ± 0.1-glargine,

p<0.05]. The serum IGF-1 levels were significantly higher in glargine treated rats [567 ± 121

(ng/ml)-control; 1059 ± 150(ng/ml)-glargine]. The aortic 8-isoprostane levels were decreased

significantly in the glargine treated rats [(921 vs. 2566 pg/mg protein; p<0.05]. Intensity of

nitrotyrosine staining was significantly lower in both the insulin treated animals compared to

control; being lowest level in the glargine treated animals. Fasting and post –prandial glucose

was unchanged.

CONCLUSION–: We conclude that insulin glargine (or to a lesser extent glulisine) attenuates

intimal hyperplasia following ba

effects are independent of changes in glucose a

IGF -1 and decreased vasc

14

Page 15: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

CONTRIBUTIONS OF LIPIDS AND DIABETES IN ISCHEMIC INJURY IN A RAT MODEL OF THE METABOLIC SYNDROME

1 2 Stephen W. Schaffer and Mahmood Mozaffari

ollege of Georgia, Oral Biology and Maxillofacial Pathology, Augusta, GA, USA

arts obtained from glucose intolerant, borderline type 2 diabetic rats are resistant to

re was induced in glucose intolerant and control rats by performing a

.

group although they were reduced in the glucose intolerant, hypertensive

rential that existed between the hypertensive

nd hypertensive, glucose intolerant rats. In conclusion, fat feeding and elevations in

usion pressure increase the susceptibility of the glucose intolerant heart to

ia/reperfusion. These findings are relevant to the metabolic syndrome that manifests

sistance, dyslipidemia and systemic hypertension.

1University of South Alabama, Pharmacology, School of Medicine, Mobile, AL, USA and 2Medical C

He

ischemia, an effect attributed to elevations in protein kinase C and reduction in [Ca2+]i during

the ischemia/reperfusion insult. To examine the effect of hypertension on ischemic injury,

high blood pressu

uninephrectomy procedure and feeding the animals a high salt diet. Surprisingly, infarct size

was reduced in the salt sensitive hypertensive animals, with the reduction in infarct size

greatest in the glucose intolerant, hypertensive animals. However, an elevation in perfusion

pressure prevented the beneficial effects of hypertension on infarct size, although infarct size

was still reduced in the hypertensive, glucose intolerant rats despite the elevation in perfusion

pressure

Another factor that influences infarct size is fat feeding, although the response differs

in the glucose intolerant and tolerant rats. Over an 18 week period, fat feeding had no effect

on plasma insulin and leptin levels of the hypertensive, glucose intolerant rat, but resulted in

an increase in plasma triglyceride levels, a rise in the degree of glucose intolerance and a

decline in contractile function. By contrast, chronic fat feeding led to elevations in body

weight, plasma leptin content and the degree of insulin resistance of the hypertensive rat.

Rates of contraction (+dP/dt) and relaxation (-dP/dt) were largely unaffected by fat feeding in

the hypertensive

group. Initiation of regional ischemia led to a severe reduction in contractile function in both

groups, with the contractile defect worsening during the ischemic period. While fat feeding

did not affect infarct size of the hypertensive rat, it worsened that of the hypertensive, glucose

intolerant rat, causing the abrogation in the diffe

a

perf

ischem

as a cluster of insulin re

15

Page 16: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

CHANGES IN PPAR GENE EXPRESSION ARE INVOLVED IN MYOCARDIAL RESPONSE TO ISCHEMIC INJURY IN NORMAL AND DISEASED HEART:

ELEVANCE TO PLEIOTROPIC EFFECTS OF STATINS

1Inst Heart Res, Slovak Acad Sci & CEKVY SAS; Dept Pharmacol and Toxicol, Fac Pharm, 3

of CH. In the present study we characterized the effect of treatment with S (10

mg/kg/

c target in the

anagement of ischemic heart disease. Supported by Grants VEGA SR 2/0173/08, 1/4296/07

R Tana Ravingerova1, Adriana Adameova2, Tara Kelly3, Maria Zazrivcova1, Dezider Pancza1, Antigone Lazou3

2

Comenius Univ, Bratislava, SR; Sch Biol, Aristotles Univ, Thessaloniki, Greece

Hypercholesterolemia (H-CH) has a negative impact on ischemia/reperfusion (I/R) injury,

while lowering of serum CH by statins is widely used in the treatment of coronary artery

disease. However, statins have additional CH-independent effects. One of these pleiotropic

actions includes regulation of peroxisome proliferator-activated receptors (PPARs), the key

transcriptional regulators of lipid metabolism and energy production involved in the

mechanisms of I/R injury. We have recently shown that H-CH reduced gene expression of

both, PPAR alpha and gamma isoforms post-I/R and exacerbated an outcome of I/R injury in

the diabetic hearts, while simvastatin (S) restored their tolerance to ischemia without affecting

high levels

day, p.o.) on myocardial infarction and ischemia- and reperfusion-induced ventricular

arrhytmias in the normocholesterolemic rat hearts, as well as on the cardiac gene expression

of PPAR alpha. Regional 30-min ischemia induced by occlusion of LAD coronary artery was

followed by 120-min reperfusion. The infarct size (IS; TTC staining) was expressed as a

percentage of area at risk (AR) size. Gene expression of PPAR alpha was measured in the left

ventricular tissue at baseline conditions and after I/R (RT-PCR). Following 5 days, mRNA

levels of PPAR alpha in the hearts of treated rats were increased by 78% as compared with

the non-treated controls. In the S-treated animals, IS/AR was significantly smaller (11.5 ±

0.4% vs. 33.7 ± 4% in C; P<0.05). During ischemia, the incidence of ventricular arrhythmias

was reduced in the treated group. In addition, treatment with S resulted in attenuation of

postischemic contractile dysfunction and lower severity of reperfusion-induced arrhythmias.

Enhanced resistance to I/R injury was associated with preservation of baseline mRNA levels

of PPAR after I/R in these hearts in contrast to their downregulation in the non-treated group

(post I/R reduction by 65%). In conclusion, changes in the expression of PPAR may

potentially account for cardioprotective effects of statins under conditions of

normocholesterolemia. PPAR might represent an important therapeuti

m

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Session II. Sympathetic nervous system and RAAS - known or yet unknown?

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CHRONI HAVE DIFFERENTIAL EFFECTS ON ELECTRICAL AND MECHANICAL ACTIVITIES

F HEART

elma Turan epartments of Biophysics, Pharmacology, Faculty of Medicine, Ankara University, Ankara, urkey

ardiovascular diseases are major causes of mortality in patient population and beta-

drenergic blockers are one of the most frequently prescribed cardiovascular drugs. Although

ere are significant differences among agents, their clinical effects are predictable. Since

ropranolol (PROP) and timolol (TIM) are nonselective agents with different beta-potency,

e wanted to examine the long-term effects of selective blocker, PROP (25 mg/kg/day) – or

IM (5 mg/kg/day) administrations (intragastrically), on hemodynamic and action potential

arameters, and Ca2+-release mechanisms of the rat hearts. Maturation-induced depressions in

ft ventricular developed pressure (LVDP; 30-50%)) were significantly restored with TIM

ut not PROP) treatment. In addition, markedly prolonged two late repolarization phases of

ction potential with maturation were normalized with TIM treatment. Maturation-induced

ignificant inhibition in L-type Ca2+-current and marked increase in intracellular basal Ca2+

vel were recovered completely with TIM treatment. In addition, a significant decrease in

e Ca2+ transients (obtained with electrical stimulation) was observed with maturation, and

is value was shown to decrease further after TIM treatment while it was completely

ormalized with the PROP treatment. As summary, present data suggest that TIM improved

ft ventricular function due to its beneficial effect on Ca2+-influx in maturation- and/or aging-

duced depressed cardiac function while PROP showed different effect. Therefore, our

sults suggest that although treatment with beta-adrenergic blockers appear to confirm the

le of adrenergic pathway in heart function of adult rats; there are differences in the effect of

dividual beta-adrenergic blocking agent when particular clinical benefits are addressed

107S427 and TUBITAK-COST-107S304).

C TREATMENTS WITH BETA-ADRENERGIC BLOCKERS

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(Supported by TUBITAK-SBAG-

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BRAIN MECHANISMS CONTRIBUTING TO SYMPATHETIC HYPERACTIVITY AND HEART FAILURE: CRITICAL ROLE FOR TISSUE RAAS Frans HH Leenen

ttawa Heart Institute, Ottawa, Ontario Canada

ascular regulation has been emerging in recent

ral infusions of an

ldosterone synthase inhibitor, indicating that the MR activation in the CNS post MI depends

n aldosterone, locally produced.

n conclusion, beyond its classical role as a hormone regulating renal Na+-transport,

ldosterone exerts profound effects on arteries and the heart. Its central actions are recently

merging, and appear to play a crucial role in cardiovascular homeostasis, when challenged

y high salt intake, or decreased cardiac function.

eferences:

University of O

he major role of the brain RAAS in cardiovT

years. The presence of enzymes involved in steroidogenesis (including aldosterone synthase),

MR and 11β–HSD-2 has been well documented in several parts of the CNS including the

hypothalamus, and a functional role for locally in the CNS produced aldosterone is becoming

apparent. Sympatho-excitatory and hypertensive responses to central infusions of aldosterone

are MR mediated. MR activation by aldosterone appears to activate CNS pathways by

enhancing ENaC activity followed by “ouabain” release and AT1-receptor stimulation. These

CNS mechanisms are activated by central infusions of Na+-rich aCSF and by high salt intake

in Dahl S and SHR. Most of the MR activation appears to be due to an increase in locally

produced aldosterone. Interestingly, the CNS pathways mediating sympathetic hyperactivity

in rats with CHF post MI involve the same mechanisms, ie MR activation via ENaC increases

central “ouabain” release and AT1-receptor stimulation. Studies with transgenic rats with

absent glia angiotensinogen demonstrated that the latter involves locally in the CNS produced

Ang II. The actual CNS pathways involve AT1-receptor stimulation in the PVN, but the

proximal part has not yet been clarified. It is possible that an increase in circulating Ang II

post MI leads to chronic activation of neurons in circumventricular organs such as the SFO

and to activation of this neuromodulatory pathway acting as an amplifier. MR activation in

the CNS not only contributes to the sympathetic hyperactivity, but also to activation of

several other peripheral systems such as the circulatory and cardiac RAAS as well as well the

increase in circulating cytokines. Not surprisingly, these central pathways also play a major

role in disease progression post MI. Chronic central infusion of a MR blocker prevents a

major part of the structural remodeling of the heart post MI, as well as a major part of the

decrease in LV function. Similar results can be obtained by chronic cent

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1. Lal A, Veinot JP, Leenen FHH. Cardiovas Res 64:437-447, 2004.

. Wang H, Huang BS, Ganten D, Leenen FHH. Circ Res 94:843-849, 2 2004.

c Res (Editorial). 101:221-223, 2007

. Cardiovasc Res, 2008 (in

3. Leenen FHH. Cir

4. Huang B, White R, Ahmad M, Tan J, Jeng AY, Leenen FHH

press)

20

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ANGIOTENSIN II- INDUCED Gi SIGNALING IN HYPERTENSION

ity of Montreal, Montreal, Quebec,

We have previously shown an enhanced expression of Giα proteins in spontaneously

ypertensive rats (SHR) that precedes the development of hypertension. Since the levels of

asoactive peptides including angiotensin II (Ang II) have been shown to be enhanced in

HR, the present studies were undertaken to examine the role of Ang II and associated

ignaling in enhanced expression of Giα proteins in SHR. Aortic vascular smooth muscle

ells (VSMC) from 12 week-old SHR and Wistar-Kyoto rats (WKY) were used for the

resent studies. VSMC from SHR exhibited enhanced expression of Giα-2 and Giα-3 proteins

s compared to age-matched WKY. The increased levels of Giα-2 and Giα-3 were restored

control WKY levels by captopril; angiotensin converting enzyme inhibitor, losartan; an

T1 receptor antagonist as well as PD 98059; a selective inhibitor of MAP kinase. The

vels of superoxide anion (O2-) that were increased in SHR were also restored to control

KY levels by losartan. Furthermore, treatment of VSMC with antioxidants such as N-

cetyl-L-cysteine (NAC) or diphenyleneiodonium (DPI) and PD 98059 reversed the enhanced

xpression of Giα-2 and Giα-3 proteins and enhanced ERK1/2 phosphorylation to control

vels. The growth factor receptor inhibitors such as the inhibitors of platelet-derived growth

ctor receptor (PDGFR), epidermal growth factor receptor (EGFR) and insulin like growth

ctor receptor (IGFR) were also able to restore the enhanced levels of Giα-2 and Giα-3

roteins and enhanced ERK1/2 phosphorylation to control levels. In addition, the

hosphorylation of PDGFR, EGFR and IGFR was enhanced in VSMC from SHR as

ompared to WKY which was restored to control levels by captopril. These results suggest

at enhanced levels of Giα in SHR may be attributed to Ang II-induced enhanced oxidative

tress which exerts its effects through growth factor receptor-mediated MAP kinase signaling

athway. (Supported by grant from CIHR).

Madhu B. Anand-Srivastava Department of Physiology, Faculty of Medicine, UniversCanada

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Session III. NO and cardiovascular protection

22

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NITRITE THERA

hilip J. Kadowitz ew Orleans (USA)

PY FOR CV DISEASE

PN

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PERIPHERAL AND CENTRAL REGULATION OF BLOOD PRESSURE: THE OLE OF NITRIC OXIDE

stitute of Normal and Pathological Physiology and Centrum of Cardiovascular Research, lovak Acedemy of Sciences and Centrum of Experimental Medicine, Bratislava, Slovak epublic

echanisms of NG-nitro-L-arginine methyl ester (L-NAME)-induced hypertension involves

ore than a simple inhibition of nitric oxide production with consequent decrease of

asorelaxant activity. Nevertheless, attenuated vascular relaxation and enhanced contraction

different parts of vascular tree belong to the first factors contributing to the increase of

lood pressure (BP). Among other factors, increased level of prostaglandins, reactive oxygen

pecies and increased activity of renin-angiotensin-aldosterone system and sympathetic

ervous system were demonstrated. Since a serious role of nuclear factor NF-κB in the

xpression of nitric oxide synthase (NOS) isoforms was reported, the goal of our study was

analyze a time course of L-NAME effect on nitric oxide synthase (NOS) particular

oforms and NF-κB protein expressions, total NOS activity and BP in rats. NOS activity was

ecreased after 4 weeks of L-NAME treatment in all tissues investigated. We demonstrated

at prolonging the L-NAME treatment to 7 weeks increased NOS activity in the aorta, heart,

nd kidney while NOS activity in the brain parts like brainstem, cerebellum and brain cortex

as decreased more significantly. Further, increased expression of eNOS protein may be

sponsible for increased NOS activity in peripheral tissues, while decreased expression of the

ame NOS isoform in the brainstem, cerebellum and brain cortex led to a more pronounced

ecrease of NOS activity in these parts of brain. Analysis of NF-κB (p65) protein expression

onfirmed the regulatory role of eNOS transcription and/or expression. Since BP increase

ersisted after 7 weeks of L-NAME treatment, we hypothesized that central regulation of BP

predominant in L-NAME-induced hypertension.

upported: VEGA 2/6148/26, APVV-0586-06 and APVV-0538-07.

R Olga Pechanova InSR M

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MOLECULAR MECHANISMS OF VASCULOPROTECTIVE EFFECT OF NITRIC OXIDE Ashok K. Srivastava Centre de Recherche, Centre hospitalier de l’Université de Montréal (CHUM), Montreal, Quebec, Canada

Nitric oxide (NO), in addition to serving as an important vasodilator, has also been suggested

to serve as an antimitogenic and antihypertrophic agent for growth factors and vasoactive

peptides such as endothelin-1 (ET-1) in vascular smooth muscle cells (VSMCs). However, the

exact mechanism by which NO exerts its antimitogenic and antihypertrophic effects is not

well defined. Here we have demonstrated that treatment of A-10 VSMCs with S-nitroso-N-

acetylpenicillamine (SNAP) or sodium nitroprusside (SNP), two NO donors, attenuated the

ET-1-enhanced phosphorylation of several key components of mitogenic, growth promoting

and hypertrophic signaling pathways such as ERK1/2, PKB and Pyk2. On the other hand, the

inhibition of the endogenous NO generation by using N-nitro-L- arginine methyl ester (L-

NAME), a NO synthase inhibitor, increased the ET-1-induced phophosphorylation of these

signaling components. Since, NO mediates its effect principally through a cyclic GMP/ and

soluble guanylyl cyclase (sGC) pathway, we investigated the role of these molecules in NO

action. 8-Br-cGMP, a cell permeant and non-metabolizable analogue of cGMP, exhibited a

similar effect as NO donors and the pharmacological blockade of sGC reversed the inhibitory

effect of NO on ET-1-induced responses. SNAP treatment also inhibited the protein synthesis

induced by ET-1. Taken together, these data demonstrate that NO, in a cGMP-dependent

manner, attenuated ET-1-induced signaling events and hypertrophy in VSMC. It may be

suggested that suppression of ET-1 signaling pathway and hypertrophic responses by NO

contributes towards its vasculoprotective effects.

(Supported by CIHR).

25

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PEROXYNITRITE-INDUCED PROTECTION AGAINST ARRHYTHMIAS Agnes Vegh, Attila Kiss, Laszlo Juhasz

ology and Pharmacotherapy, University of Szeged, Szeged, Hungary

gen derived radicals, generated during ischaemia and reperfusion, are

rapidly react and form other highly reactive species, such as peroxynitrite, which is one of the

creased superoxide production rather than to

formation, and this effect might explain the marked antiarrhythmic

ffects of preconditioning and peroxynitrite. There are, of course, a number of possible ways

y which NO may result in antiarrhythmic protection. These include the modulation of

uperoxide production, the release of catecholamines and acetylcholine and the regulation of

e influx and uptake of calcium, etc. They role in the antiarrhythmic protection will also be

iscussed.

Department of Pharmac Nitrogen and oxy

major contributors of myocardial and endothelial dysfunction, cell necrosis, and of

reperfusion-induced ventricular arrhythmias. However, there is accumulating evidence that

high nanomolar or low micromolar concentrations of exogenouly administered peroxynitrite

can be cardioprotective. For example, short (5 min) periods of peroxynitrite infusion, given by

intracoronary route in anaesthetised dogs, induce a preconditioning-like antiarrhythmic

protection, and reduce the formation of endogenous peroxynitrite following a prolonged

period of ischaemia and reperfusion. Such a reduced generation of peroxynitrite (assessed by

the measurement of nitrotyrosine formation in tissue samples taken from the ischaemic

myocardium soon after the reperfusion) may also occur in dogs that are subjected to similar

brief periods of coronary artery occlusion (preconditioning) 5 min prior to a more prolonged

(25 min) ischaemia and reperfusion insult. Since peroxynitrite is formed from equimolar

concentrations of NO and superoxide, a decrease in peroxynitrite generation should result

from either a reduced nitric oxide or a reduced superoxide production. Both preconditioning

and the administration of peroxynitrite increase the plasma nitrate/nitrite (NOx) levels and

these are maintained or even further increased during the prologed test ischaemic period. In

contrast, superoxide production, determined by confocal laser microscopy in tissue samples

taken at reperfusion, markedly decreases following preconditioning and peroxynitrite

adminsitration. These results suggest that under in vivo conditions the reduction in

endogenous peroxynitrite formation is due to a de

a modification of NO

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EFFECT OF PROVINOL ON CARDIAC NA,K-ATPASE DURİNG HYPERTENSİON

Veronika Javorkova1, Lucia Mezesova1, Olga

Institute of Normal and Pathological Physiology, Slovak

Norbert Vrbjar1, Jana Vlkovicova1, Pechanova2, Ramaroson Andriantsitohaina3

1Institute for Heart Research, SAS, 2

Academy of Sciences, Bratislava, Slovakia, 2Biologie Neuro-Vasculaire Intégrée, UMR INSERM 771-CNRS 6214, School of Medicine, Angers, France.

We investigated whether administration of red wine polyphenolic compounds (Provinol)

protects the cardiac Na,K-ATPase during the developing and sustained hypertension. The

hypertension was induced in male rats (LN group) by the nitric oxide synthase (NOS)

inhibitor, L-NAME (40 mg·kg-1·day-1). The Provinol (40 mg·kg-1·day-1) was applied during

development (LNPF4) and persistence of hypertension (LNPF7/3). The enzyme kinetics of

Na,K-ATPase was used for characterization of ATP- and Na+-binding sites. NO-deficient

hypertension by itself lowered the activity of Na,K-ATPase resulting in significant decrease

of Vmax with unchanged Km value for ATP, but with decrease of the enzyme affinity to Na+ as

shown by the 59% increase of KNa value in LN, as compared to controls. Concerning the

ATP-binding site, administration of Provinol to hypertensive animals induced a further

significant decrease of Vmax value by 38% in LNPF4 and by 50 % in LNPF7/3 as compared to

LN. The affinity of the ATP-binding site was significantly decreased in LNPF4 only, as

suggested by marked increase of Km value by 52%. Concerning the Na+-binding site,

administration of Provinol induced a marked increase of Na,K-ATPase activity especially in

the presence of low concentrations of Na+, resulting in decrease of KNa value by 72 % for

LNPF4 and by 69 % for LNPF7/3 as compared to LN. Administration of Provinol induced

different effects on ATP-binding and Na+-binding sites of the cardiac Na,K-ATPase. In the

vicinity of ATP-binding site the effect of Provinol was deleterious, resulting in worsened

utilization of substrate by the enzyme. In the vicinity of Na+-binding site the effect of

Provinol was protective, resulting in increased affinity of the enzyme to sodium.

This research was supported by Slovak Grant Agencies (grant No. VEGA 2/7127/27, APVV-

51-059505).

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Session IV. Adaptative (protective?) mechanisms in cardiovascular system

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THE TRANSCR ULATOR OF CARDIAC COL SION

ichael Czubryt, Leon Espira and Lise Lamoureux stitute of Cardiovascular Sciences, St. Boniface Hospital Research Centre and Department

f Physiology, University of Manitoba, Winnipeg, Canada

ardiac fibroblasts synthesize collagens as part of the extracellular matrix, which contributes

the mechanical strength of the myocardium. In response to stresses such as myocardial

farction or hypertension, the heart undergoes remodeling marked by cardiomyocyte

ypertrophy, alterations in chamber dimensions and phenotype conversion of fibroblasts into

yofibroblasts that synthesize large amounts of fibrillar collagens. Excessive collagen

ynthesis impairs contraction and relaxation, eventually contributing to cardiac failure. The

evelopment of improved anti-fibrotic therapies requires a greater understanding of the

ontrol of collagen synthesis. Of note, the transcriptional regulators of collagen synthesis are

ot fully known.

We report here that the basic helix-loop-helix transcription factor scleraxis regulates

e expression of collagen Iα2, the primary collagen expressed in cardiac fibrosis. We show

at scleraxis is expressed in cardiac fibroblasts, and its expression level increases two-fold as

broblasts phenoconvert to myofibroblasts. Stimulation of cardiac fibroblasts with the pro-

brotic growth factor TGF-β induces a four-fold increase in scleraxis expression.

verexpression of scleraxis in NIH 3T3 fibroblasts is sufficient to up-regulate the expression

f collagen Iα2. By in silico analysis, we have identified several putative scleraxis binding

ites in the collagen Iα2 promoter which are conserved in mice, rats and humans. In in vitro

ciferase assays, scleraxis strongly transactivated the collagen Iα2 promoter. Deletion

xperiments reveal that transactivation is critically dependent on the DNA-binding motif of

cleraxis, and is attenuated by deletion of a protein-interaction moiety. Taken together, our

sults strongly support the hypothesis that scleraxis directly regulates cardiac collagen gene

xpression, and may play a key role in cardiac fibrosis.

upported by the Heart & Stroke Foundation of Canada and the Manitoba Medical Service oundation.

IPTION FACTOR SCLERAXIS IS A NOVEL REGLAGEN GENE EXPRES

MIno C

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EXPRESSION OF THE CARDIAC SIGMA RECEPTORS IN RAT AND MOUSE UNDER PHYSIOLOGICAL AND VARIOUS PATHOLOGICAL CONDITIONS

Excellence for Cardiovascular esearch, Slovak Academy of Sciences, Bratislava, Slovakia

culum leads to modulation of cardiac contractility after stimulation of

cardiom

e can assume that sigma receptors

Marie Novakova, 1Olga Krizanova Department of Physiology, Faculty of Medicine, Masaryk University Brno, Czech Republic 1Institute of Molecular Physiology and Genetics, Centre of R Sigma receptors are recently cloned binding sites for several classes of psychotropic drugs

and steroids. They exist in several subtypes and have been localized in many tissues,

including the heart muscle. A considerable effort has been done to explain the intracellular

mediation of sigma signalling and its physiological role. However, the most important

discovery for understanding the sigma signalling has not yet been done: the endogenous

ligand remains obscure.

In our previous studies we have proved that the IP3 stimulated release of calcium from the

sarcoplasmic reti

yocytes or multicellular heart preparations with sigma ligands. Moreover, we

observed prominent electrophysiological changes (QT prolongation, arrhythmias occurrence)

in isolated rat and guinea pig hearts.

The aim of the present study was to examine the gene expression of sigma receptors in the left

ventricles of rat heart in physiological situation (ageing) and under the effect of various

stressors (hypoxia, cold, and immobilization). We have found that gene expression of sigma

receptors is not significantly changed during ageing, but it is upregulated by strong stress

stimuli, such as immobilization and/or hypoxia. Nevertheless, cold as a milder stressor has no

effect on sigma receptor’s mRNA levels. Signalling cascade of sigma receptors is dependent

on IP3 receptors, since silencing of both, type 1 and 2 IP3 receptors resulted in decreased

mRNA levels of sigma receptors.

Physiological relevance of sigma receptors in the heart is not fully elucidated yet.

Nevertheless, based on the already published data w

participate in contractile responses in cardiomyocytes.

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INDUCTION OF CARBONIC ANHYDRASE IX IN HYPOXIC RAT CARDIOMYOCYTES: ROLE OF THE MITOCHONDRIA 1Attila Ziegelhöffer, 2Tereza Holotnakova, 1Miroslav Ferko, 1Jana Mujkosova, 1Tana

ab.

hys. Inf., Comenius Univ., Bratislava, Slovakia

) Elucidate the role of mitochondria in control of CA IX expression

ethyl ester of succinate (DMS), diazoxide (DZO) and

much less potent in inducing car9 expression. Surface

xtrusion of succinate and free radicals

hich accumulate in the mitochondria (MIT) due to inhibition the tricarboxylic acid cycle by

OX, succinate dehydrogenase inhibitors or other means. MIT actively contribute to

isruption of O2 sensing and via this mechanism support the expression of CA IX in CM.

upport: Grants APVV 51-027404 and 51-024805, VEGA 2/0173/08, 02/7126/27 as well as

e order of the Slovak Government SP 51/0280901.

Ravingerova, 3Olga Ulicna, 4Iveta Waczulikova, 2Silvia Pastorekova, 2Jaromir Pastorek1Inst. Heart Res., Ctr. Excel. Cardiovasc. Res., SAS.; 2Inst. Virol. SAS.; 3LPharmacobiochem. 3rd Dpt. Int. Med., Fac. Med.; 4Dpt. Nuclear Phys. Biophys., Fac. Math., P

Background: CA IX is a cell membrane-bound isoform of CA acting in cell adhesion and pH

control. It is strongly induced by hypoxia (HOX) and often associated with tumors. The

presence of CA IX in the myocardium was first time revealed by us in 2005. Aims: i)

Ascertain whether CA IX is present in normoxic (NOX) as well as in HOX rat

cardiomyocytes (CM); ii

in CM via modulation of O2 sensing by influencing the HIF-1α pathway. Experimental:

Isolated primary (P) CM and/or immortalized H9c2 CM (I) maintained in culture for 3 weeks

before the experiment. HOX induced with 2 % O2 lasted 48 h; CA IX expression was detected

by immunofluorescence, RT PCR and immunoblotting. HIF-1α pathway modulators applied:

dimethyloxalylglycine (DMOG), dim

tempol (TL). Results and Discussion: In PCM, CA IX and VEGF were present already in

NOX. HOX induced a 2-fold increase in CA IX and strong rise in levels of HIF-1α, Glut-1

and iNOS, but only a moderate elevation of VEGF. The high magnitude of induction of CA

IX gene in comparison with that of the VEGF may be caused by much closer localization of

its HIF binding element on the Ca9 promoter to the transcription initiation site. Similarly as in

PCM, also in ICM were the rodent CA gene (car9) transcription and CA IX protein

expression strongly induced by HOX as well as by DMOG and less by TL. Other modulators

such as DMS and DZO were

localization of CA IX was confirmed in all cell types investigated. Conclusions: CA IX is

present in CM also in NOX and its expression is intimately involved in molecular responses

to HOX and to chemical disruption of O2 sensing. By e

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IS MYOCARDIAL GAP JUNCTION CHANNEL PROTEIN, CONNEXIN-43, A KEY PLAYER OR BYSTANDER IN MODULATION OF CARDIAC LETHAL

RRHYTHMIA SUSCEPTIBILITY?

l and metabolic cell-to-cell communication

ia gap junction connexin channels ensures myocardial synchronisation. In turn, the defects in

A Narcis Tribulova Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia Background and purpose: Functional electrica

v

connexin expression and/or distribution linked with disorders of intercellular communication

are thought to be arrhythmogenic facilitating occurrence of lethal arrhythmias. We examined,

therefore, topology, expression and phosphorylation of major cardiac gap junction channel

protein, connexin-43 (Cx43) as well as susceptibility of the heart to ventricular fibrillation

(VF) in various models of cardiomyopathy. Experimental approach: Experiments were

conducted on male adult spontaneously hypertensive rats, hyperthyroid rats, STZ-diabetic rats

and diabetic rats treated with thyroid hormone as well as age-matched healthy control rats.

Ventricular distribution of Cx43, its expression and phosphorylation were analysed using

immunofluorescence and Western blotting with mouse MAb. Susceptibility to VF was

examined in isolated heart preparation using electrical stimulation or hypokalemic perfusion.

Key results: Immunodetection revealed besides end-to-end (intercalated disc-related)

enhanced expression of side-to-side Cx43 positive gap junctions in diseased rat hearts. In

addition, total Cx43 and its phosphorylated isoforms were significantly decreased in

hypertensive as well as hyperthyroid rat hearts, while increased in diabetic rat hearts

compared to controls. However, treatment of diabetic rats with thyroid hormone suppressed

both expression and phosphorylation of Cx43. In correlation, the hypertensive and

hyperthyroid rats were much more prone to develop VF, while diabetic rats were much less

when compared to healthy controls. Interestingly, the treatment of diabetic rats with thyroid

hormone increased their vulnerability to VF. Conclusions and implications:: These findings

indicate that intercellular channel protein Cx43 is likely involved in the modulation of

susceptibility of the heart to malignant arrhythmias. It appears that up-regulation of Cx43 is

associated with decrease while down-regulation with increased susceptibility to lethal

arrhythmias. This work was supported by APVV grants 51-059505 and 51-015905.

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HOW PERIPHERAL ARTERIAL DISEASE MAY PREDICT CORONARY ARTERY EVENTS Amarjit S. Arneja

nal Medicine, University of Manitoba, Winnipeg, Canada

Department of Inter

Lower extremity peripheral arterial disease (LEPAD) is a common syndrome that

affects 16% of North American and European population and is a marker of generalized

atherosclerosis. Individuals with atherosclerotic LEPAD may be asymptomatic; symptomatic

(classic claudications or atypical leg symptoms) or present with critical limb ischemia. The

most cost effective tool for detection of LEPAD is the ankle brachial index (ABI). Patients

diagnosed with LEPAD are six times more likely to die within 10 years than those without

LEPAD.

The high prevalence of diabetes, smoking, hypertension, hyperlipidemia and

hyperhomocystinemia increases the risk of developing LEPAD. Patients with LEPAD have

concomitant coronary artery disease (85%) internal carotid artery disease (60%) and are at

increased risk of atherosclerotic ischemic events including MI and stroke. All patients with

LEPAD should achieve risk reduction and specific treatment targets comparable to those

individuals with established coronary artery disease.

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VARIABILITY OF CONNEXIN-43 EXPRESSION IN THE AORTA OF RATS WITHDIFFERE

NT GENOTYPE

va

Connexin-43 (Cx43) is a protein of gap junctional intercellular channels which enable rapid

isms involved in

rat strains were used: Wistar (W) and Lewis (L) rats, and spontaneously

hyperte

otensive rats, more abundant fluorescent

pots were found in aorta of L than in W; in hypertensive rats stronger reaction was seen in

orta of hHTG than in SHR. In addition, endothelial Cx43 spots were focally absent in SHR.

estern blot demonstrated presence of two Cx43isoforms in aortic tissue of all rats:

hosphorylated (P1) - related to coupling of gap junction channels and unphosphorylated (P0) -

lated to channels uncoupling. Remarkable differences in total Cx43 expression were also

bserved between used strains: i.e. it was higher in aorta of L than in W and in aorta of hHTG

s compared to SHR (p<0.01). Ultrastructural analysis demonstrated frequent occurence of

ndothelial cell abnormalities of aorta of hypertensive rats. Endothelium-dependent relaxation

f aorta was diminished in SHR and hHTG rats (p<0.05). Blood pressure was 213±4.46 mm

g in SHR and 163±3.25 mm Hg in hHTG (p<0.01). Nonsignificant differences in blood

ressure were found between W and L. The present study demonstrated that there exists

ariability of the aortic Cx43 expression among laboratory rats with different genotype that

ight contribute to development of the arterial functional and structural abnormalities.

upported with APVV-51-059505.

Ludmila OkruhlicoInstitute for Heart Research, SAS, Bratislava, Slovak Republic

conduction of electrical and chemical signals along the vessel, generating vasomotor responses.

Changes in Cx expression may thus represent one of critical mechan

development of cardiovascular diseases. Response of cardiovascular system to

pathophysiological situations shows high inter-individual variation. Involvement of genetic

factors in this variability has also been demonstrated. The aim of the work was to study Cx43

expression in aorta of rats, differing in their genotype. Two normotensive and two hypertensive

1-year-old

nsive (SHR) and hereditary hypertriglyceridemic (hHTG) ones. Cx43 in situ

localization was detected using immunofluorescent method. Cx43 expression was determined

by Western blot analysis and GelPro System. Electronmicroscopy was used for ultrastructural

characterization of endothelial integrity. Blood pressure and NO-dependent relaxation of aortae

were measured as well. Immunolabeling of Cx43 was identified in endothelium and media of

all rats, however with its different intensity: in norm

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Session V. New aspects of heart failure

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C

YTOKINE IMBAL

awan K Singal, Sanjiv Dhingra, Jan Slezak1 and Anita K Sharma stitute of Cardiovascular Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, anada. Institute of Heart Research, Slovak Academy of Sciences, Bratislava, Slovak epublic

ifferent cytokines in heart failure are modified in a characteristic manner and the details of

eir precise role in this condition are not known. In this regard, tumor necrosis factor (TNF) -

lpha has been suggested to play a role in the progression of heart failure. Interleukin 10 (IL-

0) antagonizes some of the effects of TNF-alpha. We have already shown that heart failure

ubsequent to MI is associated with the decrease in IL-10/TNF-alpha ratio and that, IL-10

odulates the TNF-alpha induced oxidative stress in isolated cardiomyocytes. However,

tracellular signaling events responsible for this are not known. Present study investigates

le of p38 and ERK 1/2 MAP kinases in TNF-alpha induced cardiomyocyte apoptosis and its

odulation by IL-10. Cardiomyocytes isolated from Sprague Dawley rats were exposed to

NF-alpha (10ng/ml), IL-10 (10ng/ml) and IL-10+TNF-alpha (ratio 1) for 4hrs. H2O2

ositive control) and antioxidant trolox (20 μmol/L) were used to confirm involvement of

xidative stress. H2O2 (100 μΜ) increased oxidative stress and apoptosis, TNF-alpha

imicked these effects. Exposure to TNF-alpha increased ROS production, caused cell injury,

creased the number of apoptotic cells and Bax/Bcl-xl ratio. This change was associated with

n increase in p38 and a decrease in ERK 1/2 phosphorylation. IL-10 by itself had no effect

n these MAP kinases, but it prevented TNF-alpha induced changes. Trolox mitigated TNF-

lpha induced changes. Pre-exposure of cells to p38 inhibitor SB-203580, prevented TNF-

lpha induced changes. Inhibition of ERK pathway with PD98059 attenuated protective role

f IL-10 against TNF-alpha induced effects. Present data provide evidence that IL-10

fluences the activation of p38 and ERK 1/2 thereby modulating TNF-alpha induced

xidative stress and cardiomyocyte apoptosis (supported by CIHR).

ANCE IN HEART FAILURE

PInCR D

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RENAL DYSFUNCTION AND HEART FAILURE Jan Murin, Gabriel Kamensky 1st Internal Department, University Hospital, Bratislava, Slovakia 5th Internal Department, University Hospital, Bratislava, Slovakia Evidence for the relationship between renal insufficiency (RI) and cardiovascular (CV) events

is present not only in the dialysis population but also is extended to subjects (heart failure

[HF] patients [p] included) with more moderate (even mild) RI.

There is an association of CV events with renal function in p with HF or post

myocardial infarction (MI): (a) PRIME II study (stable advanced HF, NYHA III/IV, EF< 35

%, 1906 p, glomerular filtration (GF) by Gault-Cockroft) – quartiles of GF (Q1 vs Q4) versus

all cause mortality with HR of 2,85 (S), (b) CATS trial (baseline renal function, prediction of

HF development after anterior MI, 298 p, 1 year follow-up [FU]: HF in 24 % p (best tertile),

28,9 % p (middle) and 41,2 % p (worst), (c) VALIANT study (MI p with LV dysfunction or

HF, 14 527 p, 25 m FU) – each GF of 10 ml/min below 81 ml/min means 1,1 fold increased

risk of death/nonfatal CV complications.

We should think of RI in p with HF or risky for HF development. Better treatments

here (neurohormonal drugs) improve prognosis.

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MECHANISMS OF SUBCELLULAR REMODELING IN CONGESTIVE HEART AILURE

f Medicine, University of Manitoba, Winnipeg, Canada R2H 2A6

associated with myofibrils (MF), sarcoplasmic reticulum (SR) and sarcolemma (SL)

rem estive heart failure,

echanism

odeling and reduce the depression in the activities

ay be due to prolonged

ctivation of multiple hormonal systems. (Supported by a grant from the Canadian Institutes

f Health Research)

F Naranjan S. Dhalla Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Facultyo Although cardiac remodeling (changes in shape and size of the heart) has been shown to be

odeling (changes in biochemical and molecular composition) in cong

the m s of these alterations are not fully understood. Since congestive heart failure is

invariably associated with activation of renin-angiotensin system (RAS), sympathetic nervous

system (SNS) and serotonergic system (STS), we have tested the effects of blocking these

systems on subcellular remodeling in hearts failing due to myocardial infarction in rats.

Marked alterations in the activities, protein contents and gene expression of MF, SR and SL

were observed in the failing hearts 8 weeks upon inducing myocardial infarction. Treatments

of infarcted animals with blockers of RAS, SNS and STS for 5 weeks were found to improve

cardiac function, attenuate subcellular rem

of MF, SR and SL in the failing hearts. These data suggest that heart dysfunction, cardiac

remodeling and subcellular remodeling in congestive heart failure m

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ALTERED CONTRACTILE PROTEIN PHOSPHORYLATION DURING HEART FAILURE Zoltan Papp Division of Clinical Physiology, Institute of Cardiology, Faculty of Medicine, University of Debrecen, Hungary As a member of the G protein family, Gαq is a GTP-activated protein whose activation is

linked to the development of chronic heart failure. Through the activation of phospholipase

Cβ, Gαq is coupled to a protein kinase C (PKC)-mediated cascade, and in cardiac muscle it is

regarded as an important transducer of neurohumoral signals that include endothelin, nor-

epinephrine and angiotensin II. Hence, chronic Gαq activation presumably contributes to the

development of changes in the phosphorylation and expression of myocardial proteins leading

to myocardial hypertrophy and ultimately to heart failure.

We hypothesized that the mechanical changes in the cardiomyocytes would reflect the

involvement of PKC-modulated myofilament proteins in the pathogenensis of dilated

cardiomyopathy (DCM). Therefore, mechanical and biochemical alterations were investigated

in permeabilized cardiomyocytes along with the progression of DCM in a transgenic mouse

line overexpressing the activated Gαq protein (Tgαq*44). The isometric force, its Ca2+

sensitivity (pCa50) and the turnover rate of the actin-myosin cycle (ktr) were determined at

sarcomere lengths (SLs) of 1.9 μm and 2.3 μm before (at 4 and 10 months of age) and after

hemodynamic decompensation (at 14 and 18 months of age) in Tgαq*44 and in age-matched

ontrol cardiomyocytes. The SL-dependence of pCa50 was not different in Tgαq*44 and

ontrol hearts. In contrast, a significant increase in pCa50 was observed in the Tgαq*44

ardiomyocytes (ΔpCa50: 0.10-0.15 vs. the controls) after 10 months of age that could be

iminished by exposures to the catalytic subunit of protein kinase A (PKA). Accordingly, a

ecline in endogenous PKA activity and decreased troponin I phosphorylation were detected

fter 10 months in the Tgαq*44 hearts. Finally, the maximal Ca2+-activated force (Fo) and ktr

ere lower and the passive force (Fpassive) was higher at 18 months in the Tgαq*44

ardiomyocytes compared to the control. These mechanical alterations were paralleled by a

bust increase in β-myosin heavy chain expression in the Tgαq*44 hearts at the terminal

tage of DCM.

In conclusion, our results question the primary role of PKC-dependent mechanisms in

e myofibrillar contractile function of Tgαq*44 mice and suggested that an initial decrease of

KA signaling and subsequent changes in myofilament protein expression may contribute to

e development of dilated cardiomyopathy in Tgαq*44 hearts.

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TO BE ON TARGET – AIMED ON BETTER CARDIOVASCULAR PREVENTION: ONTARGET RESULTS.

ardiovascular mortality will still be the leading cause of death in countries also up to 2010,

study with ARB performed ever.

Patient

Andrej Dukat2nd. Department of Internal Medicine Comenius´ University, Bratislava, Slovakia. C

high-risk patient populations represent important target for their secondary prevention. Since

decades two classes of drugs affecting renin-angiotensin-aldosterone system are used in high-

risk patients with essential hypertension. HOPE study was the first, that showed significant

benefit with ACE-inhibitor ramipril in high-risk patients. ONTARGET programme was

designed in order to show the non-inferiority of ARB telmisartan in these settings.

ONTARGET is one of the largest studies evaluating patients with essential hypertension. It

recruited altogether 25 620 patients, it was the largest

s were over 55 years in high risk: present history of cardiovascular disease: coronary,

cerebral, or peripheral localization, or diabetes mellitus with complications. They were treated

with ramipril 10mg daily, or telmisartan 80mg daily, or with their combination. Follow-up pe-

riod was 5 years. TRANSCEND substudy evaluated hypertensive patients not tolerating

ACE-inhibitors. It followed-up 5 926 hypertensives, treated with telmisartan 80mg daily.

There are other 7 substudies in evaluation of other effects of secondary prevention among

hypertensives. Primary endpoint was the composite: cardiovascular death, non-fatal

myocardial infarction, stroke or hospitalization for heart failure.

Both ACE-inhibition and ARB (ramipril and telmisartan) have proved their effect in the

secondary prevention of the high-risk hypertensives, with noninferiority of telmisartan.

Combination of both above mentioned drugs did not bring any additional benefit, but an

increase of side-effects.

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BNP IN ACUTE HEART FAILURE Milan Luknar, Peter Lesny, Eva Goncalvesova

nd Transplant Department, National Institute of Cardiovascular Diseases,

he aim of

of hemodynamic parameters

AP = 10.6 +/- 4.1 mmHg vs. 7.3 +/- 2.9, p< 0.01; PCWP = 24.5 +/-

.9 mmHg vs. 18.4 +/- 4.3, p< 0.01; BNP= 739 +/- 328 pg/ml vs. 588 +/- 281 pg/ml, p<

.01). The recovery of the filling pressures to basic levels was accompanied by BNP level

crease to 742 +/- 352 pg/ml. Responders (13 pts.) and non-responders (4 pts.) showed no

ifference in the level of the ventricular filling pressure decrease. LVEDD was greater than

5 mm in 12 responders and in only one non-responder. Conclusion: In patients with acute

ecompensated HF, BNP level immediately reflects changes in ventricular filling pressures.

redictive reliability of hemodynamic changes appears to be higher in a more pronounced

ft ventricular dilation. These results seem to further support the concept of treatment

djustment and management of acute HF based on BNP levels. Repeated BNP measurement

Heart Failure aBratislava, Slovakia Introduction: Erroneous diagnosis and management of acute heart failure (HF) can have a

devastating effect on the patient. Constant effort is being performed to develop a simple non-

invasive correlate of HF. Plasma BNP and NT-proBNP are released from ventricular tissue in

response to volume overload and/or increased wall tension. In acute HF, ventricular wall

tension rises as a consequence of increased filling pressures that can be invasively measured

as pulmonary capillary wedge pressure (PCWP) and right atrial pressure (RAP). T

the study was to evaluate BNP changes in the acute hemodynamic test in patients with acute

decompensated HF. Patients and methods: 17 patients (15 males), candidates of heart

transplant (HTx), in whom severe pulmonary hypertension (PH) was diagnosed by central

hemodynamic examination (pulmonary vascular resistance >/= 4 Wood units and/or

transpulmonary gradient >/= 15 mmHg), were examined. Mean age was 50 +/- 6 yrs., mean

ejection fraction 21 +/- 5 %, left ventricle end-diastolic diameter (LVEDD) 72 +/- 9 mm. The

primary diagnosis was dilated cardiomyopathy (CMP) in 10 pts., coronary heart disease in 6

pts., and hypertrophic CMP in 1 pt. In all of them, PH reversibility test was performed using

infusion of vasodilating prostaglandine E1 (PGE1). BNP level was measured at the baseline,

at maximum hemodynamic effect of PGE1, and after resolution

to the basal values (after discontinuation of PGE1). Patients who reached 20% and greater

decrease in BNP levels in comparison with baseline values were considered responders.

Results: A significant drop in ventricular filling pressures and BNP levels was registered

during PGE1 infusion (R

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might improve the titration of treatment in patients with acute heart failure in the intensive

care setting.

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Session VI. Mechanisms of cell death and survival

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HP

YPOXIA-IND COMPLEXES ROVOKES BN ENTRICULAR YOCYTES

orrie A. Kirshenbaum stitute of Cardiovascular Sciences, University of Manitoba, Winnipeg, Canada

he cellular factor E2F-1 is known to regulate a variety of processes including G1 exit and

poptosis. Previously we have shown that E2F-1 provokes cell death of post-mitotic adult and

eonatal ventricular myocytes, however, the underlying mechanism was undetermined. In this

port we show that E2F-1 triggers cell death of ventricular myocytes through a mechanism that

irectly impinges upon the intrinsic apoptotic pathway and involves the activation of the death

ctor Bnip3. Overexpression of E2F-1 in cells caused a 4.9 fold increase (p<0.01) in myocyte

ell death compared to control cells. E2F-1 provoked mitochondrial perturbations consistent

ith hypoxic injury and the intrinsic death pathway including permeability transition pore

pening, Smac/Dibalo release and caspase-3 activation. Bnip3 gene transcription was increased

y 2.1 fold in cells expressing wild type E2F-1 but not in cells expressing a transactivation

efective mutant. During hypoxia, Rb was proteolytically cleaved and inactivated in ventricular

yocytes. In contrast to normoxic control cells, ChIP analysis verified increased binding of

2F-1 to the Bnip3 promoter during hypoxia- a finding consistent with the induction of Bnip3

anscription. The Bnip3 homologue, Nix/Bnip3L was unaffected in ventricular myocytes by

ither E2F-1 or hypoxia. Genetic ablation of E2F-1 or expression of a caspase resistant form of

b suppressed basal and hypoxia-inducible Bnip3 gene transcription. Furthermore, loss of

nction mutations of Bnip3 abrogated mitochondrial defects and cell death elicited by E2F-1.

o our knowledge the data provide the first direct evidence that de-regulated E2F-1 activity

uring hypoxia impinges upon the intrinsic death pathway through the transcriptional activation

f Bnip3 in the heart. Further we show mechanistically that basal and hypoxia-inducible

ctivation of the Bnip3 promoter is continent upon the presence of the cellular factor E2F-1.

UCED DISRUPTION OF RB/E2F-1 INHIBITORYIP3 GENE EXPRESSION AND CELL DEATH OF V

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POST-ISCHEMIC ENDOTHELIAL INJURY AND ITS PROTECTION BY ISCHEMIC PRECONDITIONING Andrzej Beręsewicz

ol, Warsaw, Poland

pproximately 25% of patients undergoing reperfusion therapy for myocardial infarction will

Postgraduate Medical Scho A

suffer from “no-reflow phenomenon” that would limit the benefits of the reperfusion. The

mechanism of the phenomenon is not completely understood but may involve reperfusion-

induced injury to the coronary endothelial cells. It is believed that by preventing this post-

ischemic endothelial injury it would be possible to increase the benefits of the reperfusion

therapies.

Based on the experiments in the model of ischemia/reperfusion (IR) in the isolated

Langendorff-perfused guinea-pig heart we propose the following mechanism of coronary

endothelial injury (Fig. 1). IR results in increased cardiac generation of endothelin (ET-1) and

nitric oxide (NO). ET-1 via ETA receptor, in the unknown mechanism stimulates superoxide

(O2-) generation by mitochondrial complex II. This mitochondrial O2

- leads to activation of

vascular NADPH oxidase. NADPH oxidase mediates the conversion of xanthine

dehydrogenase (XDH) to xanthine oxidase (XO). XO-derived O2- reacts with NO to produce a

toxic product of this reaction, e.g., peroxynitrite that mediates endothelial injury. Our

evidence indicates that ischemic preconditioning affords endothelial protection IR hearts by

preventing post-ischemic ET-1, and thus O2- generation, whereas NO generation remains

unaffected.

These results emphasize a therapeutic potential of various anti-ET-1, anti-NADPH oxidase,

nd/or anti-XO treatments in preventing endothelial injury and its adverse consequences in IR

eart.

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HYPOXIC ADAPTATION PROTECT CARDIAC CELLS VIA UPREGUALTION AUTOPHAGY IN ASSOCIATION WITH BAG-1 PROTEIN

my and Dipak K. Das onnecticut School of Medicine, Farmington,

T 06030-1110, USA.

ring hypoxia-reoxygenation in cardiac cells. However, the exact role of autophagy

induced

2 cells slightly induced the protein expression of LC3-II, an autophagic marker

protein present in the autophagosomal membrane. Also, the protein expression of Bag-1 is

also slightly induced during hypoxia-reoxygenation. However, hypoxic adaptation prior to

hypoxia reoxygenation further induced the protein expression of LC3-II and BAG-1. Our

immunofluorescence analysis further show that LC3-II level has been enhanced during

hypoxic adaptation. Furthermore, treatment with BAG-1 siRNA attenuated hypoxic

adaptation induced LC3-II and BAG-1 proteins in cardiac myoblast cells. Moreover, hypoxic

adaptation-induced cardiac cell viability studied using 3,(4,5-Dimethylthiazol-2-yl)-2,5-

diphenyltetrazolium (MTT) was reduced by Bag-1 siRNA treatment. The release of cardiac

dehydrogenase (LDH) studied using the culture supernatant was

duced by hypoxic adaptation, but Bag-1 siRNA treatment abolished the hypoxic adaptation-

tion with BAG-1 protein.

Narasimman GurusaCardiovascular Research Center, University of CC

Autophagy is an intracellular process in which cell digests its own constituents via

lysosomal degradative pathway. Though autophagy has been shown in several cardiac

diseases like heart failure, hypertrophy and ischemia reperfusion injury, the role and the

regulation of autophagy is still largely unknown. Studies have indicated that autophagy is

induced du

in hypoxia-reoxygenation is not known. Hypoxic adaptation is known to induce

survival signaling in cardiac cells, and further it is shown to protect them. BAG-1 is a

multifunctional pro-survival molecule binds protect cardiac cells from apoptosis induced by

several stimuli. In the present study, H9c2 cardiac myoblast cells were subjected to either 30

min of hypoxia followed by reoxygenation for 1 hr (HR) or hypoxic preconditioning (HPC),

where the cells were subjected to 3 cyclic episodes of 5 min hypoxia and 5 min

reoxygenation, followed by HR. Hypoxia was given by placing the cultured plates into an air-

tight hypoxic chamber placed in a humidified 37oC CO2 incubator, and passing the mixture of

95% Nitrogen and 5% CO2. Reoxygenation was given by placing back the cultured plates in a

humidified 37oC CO2 incubator saturated with air. We found that hypoxia-reoxygenation

injury in H9c

cell death marker lactate

re

induced reduction of LDH release. These results indicate that cardiac protection elicited

during hypoxic adaptation is mediated at least in part via upregulation of autophagy in

associa

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HIBERNATING MYOCARDIUM: ADAPTATION REMODELING OF CARDIAC MYOCYTES TO CHRONIC ISCHEMIA AND RETURN TO FUNCTIONAL

YOCARDIUM

rch, Slovak Academy of Sciences, Bratislava, Slovak Republic University of Manitoba, Winnipeg, Canada

are demonstrated as the most effective maneuvers. A new

M Jan Slezak, Narcis Tribulova, Ludmila Okruhlicova and Pawan Singal1

Institute for Heart Resea1Institute of Cardiovascular Sciences,

The imbalance between myocardial oxygen/nutrition supply and demand leads to a condition

of new equilibrium where myocardial necrosis is not present but cardiac myocyte slows down

to adapt to match energy supply. Molecular mechanisms, resulting in this cardiomyocyte

remodeling and adaptation in the hibernating myocardium are not fully understood.

Twenty mongrel dogs and forty rats were used to study effects of acute ischemia and chronic

hypoperfusion. Particularly, substructural changes in relation to the metabolism in stunned,

hibernating and Ca overloaded myocardium before and after reperfusion were evaluated in

detail.

Adaptation process appears to be connected with a down regulation of energy utilization that

prevents an immediate development of ischemia at the expense of an attenuated level of

contractile function. Cardiomyocytes decrease their differential functions and revert to an

embryonic character that is concerned with functions exclusively dedicated to their own

survival and resemble neonatal cardiomyocytes. Structural changes in hibernating

cardiomyocytes are characterized by loss and disorganization of myofibrils, accumulation of

glycogen, increased amount of phagosomes, alterations of nuclei in size and shape,

occurrence of small dark mitochondria of various shapes and densities and cytoplasmic

vacuolization. All these changes give the cardiac myocyte neonatal like appearance.

Extracellularly, one can find features of fibrosis and disturbed and/or diminished number of

gap junctions. Relatively large variability among cardiac myocyte physiological function and

physical performance is reflected in the substructural features of myocytes in sensitivity to the

ischemic stress. Transmural heterogeneity in the ventricular response to injury has

multifactoral origins including metabolic and flow differences in the subepicardial and

subendocardial regions of the ventricle. The extent and the degree of structural alterations of

hibernating myocardium determine left ventricular function recovery after restoration of

blood flow to the area. The most effective strategy for the treatment of hibernating

myocardium is to reinstate blood-flow by surgical revascularization or by neovascularization.

Different growth factors, angiopoietin, retroinfusion of liposomal eNOS, endothelial

progenitor cells, and resveratrol

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form of therapy for heart disease refractory to conventional therapy draws on cellular

transplantation. Supported by VEGA grant 2/7094/27

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Poster Session

ABSTRACTS OF POSTER PRESENTATIONS

Part I. OMEGA-3 FATTY ACİDS ATTE UATE DOWN-REGULATİON OF MYOCARDİAL CONNEXİN-43 İN SPONTANEOUSLY HYPERTENSİVE AND HEREDİTARY HYPETRİGLYCERİDEMİ RATS. Barbara Bacova, Katarina Dlugosova1, Miroslav Barancik1, Ludmila Okruhlicova1, Narcis Tribulova1

Faculty of Life Sciences, Comenius University, Bratislava, 1Institute for Heart Research, SAS, 2Bratislava, Faculty of Medicine, Comenius University, Bratislava, Slovak Republic

Background and purpose: Epidemiological and experimental studies suggest that omega-3

fatty acids (omega-3 FA) and lipids lowering drugs statins reduce the incidence of sudden

cardiac death, presumably due to ventricular fi illation (VF). We have previously shown that

both atorvastatin and omega-3 FA decreased susceptibility to VF in rat models of genetically-

induced dyslipidemia and hypertension (1,2). To elucidate the possible antiarrhythmic

mechanisms we focused on intercellular ch nel protein connexin-43 (Cx43), which is

responsible for cell-to-cell electrical coupling and myocardial synchronization. Experimental

approach: Spontaneously hypertensive (SHR) and hereditary hypertriglyceridemic rats

(HTR) as well as age-matched healthy Wistar or Lewis rats were fed with omega-3 FA

(30mg/day) or atorvastain (0.05mg/day) for two month and compared with untreated ones.

Some biometric parameters were monitored during and at the end of experiments. Expression

of Cx43 in left ventricles of treated and untreated rats was examined by immunobloting and

specific MAB. Key results: Omega-3 FA reduced significantly blood pressure in SHR as well

as serum triglycerides in HTR at the same leve as atorvastatin, while they did not affect body

or heart weights. Myocardial Cx43 expression was significantly reduced in left ventricles of

both SHR and HTR. Omega-3 FA and atorvastatin attenuated these abnormalities.

Conclusions and implications: Results indicate that modulation of Cx43 expression due to

omega-3 FA or atorvastatin can likely be involved in their antifibrillating effects. It is possible

that the treatment can affect turnover and/or and this should be

analyzed in further studies. This work was supported by APVV 51-059505.

1. Knezl et al. Cardiology 2007, Suppl. 1, p.19S; 2, Tribulova et al., J Interv Cardiac

Electrophysiol 2008, 21, p.180.

N

C

br

an

l

gene expression of Cx43

49

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TIS

HE EFFECT OF QUERCETI RFUSION INJURY IN OLATED RAT HEART

Monika Bartekova1, Dezider Pancza1, Olga Krizanova2, Albert Breier2, Jan Styk1, Tana Ravingerova1

1 r Heart Research SAS, Institute of Molecular Physiology and Genetics SAS, Excellence for Cardiovascular Research of SAS, Bratislava, Slovakia

of polyphenolic compounds termed

cy of flavonoids against I/R injury have demonstrated that quercetin exerts

limited evidence about the effect of quercetin on global myocardial I/R injury. Therefore, the

an only speculate

N ON ISCHEMIA/REPE

2Institute foCentre of

Introduction: Quercetin is a plant-derived dietary compound with potentially benefitial

effects on cardiovascular diseasases. It belongs to a group

flavonoids, which have been reported to possess antioxidant effects. The studies focused on

antioxidant efficien

robust protective effects in renal, cerebral and hepatic I/R models. However, there is only a

aim of the current study was to examine the effect of quercetin on isolated rat heart during

ischemia and reperfusion.

Methods: Hearts from adult male Wistar rats were isolated and perfused according to

Langendorff. After initial stabilization, hearts were 15 minutes perfused with quercetin

(15µmol/l in Krebs-Henseleit solution), just before 30 min global ischemia followed by 120

min reperfusion. Changes in left ventricular developed pressure (LVDP) and +/-dP/dtmax

were measured during initial 40 minutes of reperfusion. After the end of experiment the

hearts were stained with tetrazolium to estimate the size of infarction.

Results: Our study showed that quercetin improved postischemic recovery of functional

parameters of isolated hearts. This improvement was manifested by significantly higher

values of postischemic recovery of LVDP, +dP/dtmax and -dP/dtmin, and significantly lower

increase of diastolic pressure. Quercetin had no effect on the heart rate during the whole

experiment and coronary flow was non-significantly increased during reperfusion. Quercetin

administration also significantly reduced infarct size in hearts after 30 min global ischemia

and 120 min reperfusion.

Conclusion: Pretreatment of the hearts with quercetin had a significant positive effect on

postischemic functional recovery of isolated hearts and irreversible myocardial injury after

30-min global ischemia. Our results are in correlation with other beneficial effects of

quercetin and other flavonoids on cardiovascular system. On the other hand, our results did

not reveal potential mechanisms involved in cardioprotection. Hence, we c

about its role as an antioxidant in this protection. Supported by grant VEGA SR 2/0173/08.

50

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3-OMEGA POLYUNSATURATED FATTY ACIDS TREATMENT IMPROVES CONNEXIN43 EXPRESSION IN AORTA OF AGED SHR

udmila Okruhlicova , Narcisa Tribulova1

, Comenius niversity, Bratislava, Slovakia

ere performed on 1-year-old male SHR and normotensive Lewis

dditionaly, subcellular

ortic NOS activity by 78% in SHR. In LEW rats, PUFA only

Katarina Dlugosova1, Marcela Mitasikova1, Ruzena Sotnikova2, Iveta Bernatova3, Peter Weismann4, L 1

1Institute for Heart Research, 2Institute of Experimental Pharmacology, 3Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, 4Medical FacultyU Hypertension, associated with endothelial dysfunction and structural remodeling of the vessel

wall is also characterized by changes of connexin43 (Cx43) - protein of intercellular gap

junction channels. These enable direct communication between adjacent cells and thus

regulate vasomotor responses of vessels. 3-Omega polyunsaturated fatty acids (PUFA)

supplementation enhances protection against cardiovascular events. Therefore the aim of this

study was to examine the effect of PUFA on expression of Cx43 gap junction protein and

ultrastructure of endothelial intercellular junctions in the aorta of spontaneously hypertensive

rats (SHR). Experiments w

(LEW) rats that were divided into untreated and treated with PUFA (30 mg/day) for 2 months.

Thoracic aorta of all rats was processed for: immunofluorescence and Western blot analysis of

Cx43 and ultrastructural examination. In addition, NOS activity and relaxation of the aortae

were determined. Results showed heterogeneously reduced distribution of Cx43 fluorescent

spots in the aortic endothelium and media of SHR when compared to LEW. Parallel, Cx43

expression was also suppressed in the aorta of SHR (p<0.05). A

alterations of interendothelial tight junctions, impaired endothelium-dependent relaxation and

decreased NOS activity in the aorta of SHR. Omega-3 fatty acids significantly suppressed

blood pressure in both SHR and LEW in comparison to untreated controls (p<0.001,

p<0.003). PUFA diet increased Cx43 immunofluorescence pattern and Cx43 expression in the

aorta of SHR comparing with untreated controls (p<0.05), while no significant changes were

seen in treated LEW rats. PUFA weakly tended to improve the aortic acetylcholine-dependent

response and stimulated a

slightly affected aortic relaxation as compared to untreated rats, but they markedly stimulated

the enzyme activity. Data suggest that PUFA supplementation may contribute to improvement

of intercellular gap junctional communication and to reparation of the aortic function during

hypertension. Supported by APVV–51-059505.

51

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ENDOGENOUS PROTECTIVE MECHANISMS IN ACUTE DIABETIC RAT HEART: DIFFERENT INVOLVEMENT OF FREE RADICALS

ingerova , Attila Ziegelhöffer

rn.l Med., Fac. Med., Comenius Univ., Bratislava, Slovakia

Miroslav Ferko1, Jana Mujkosova1, Tereza Holotnakova2, Dana Kincelova3, Iveta

Waczulikova3, Olga Pechanova4, Olga Ulicna5, Tana Rav 1 1

1Inst. Heart Res., Ctr. Excel. Cardiovasc. Sci., SAS.; 2Inst. Virol. SAS; 3Dpt. Nuclear Phys. Biophys., Fac. Math., Phys. Inf., Comenius Uni.; 4Inst. Normal Pathol. Physiol., SAS; 5Lab. Pharmacobiochem., 3rd Dpt. Inte Background: Mitochondria (MIT) from hearts of rats with acute streptozotocin (STZ) -

diabetes (DIA) exhibit functional remodeling (REM) of subcellular membrane systems that is

triggered in part by free radicals (FR) and also reflects the outcome of endogenous protection

(EP). Aim: distinguish and elucidate those functions of the DIA-REM MIT membranes,

which are associated with EP in the acute DIA hearts. Experimental: DIA - induced by STZ

55 mg/kg i.p. Male Wistar rats (220+20g). Experiment was terminated on the 8th day after

STZ when the DIA rats exhibited an increase in (%): glucose 333.96, triacylglycerols 370.4,

cholesterol 153.4 and glycohemoglobin 189.6 in the blood. In heart MIT there were

investigated: oxidative phosphorylation (OP), the oxidized Q10, conjugated dienes (CD), total

MIT NOS activity, NFκB, eNOS, expression hypoxic genes and CA IX (carbonyl anhydrase),

fluidity (MF) and trans-membrane potential (MP) of the MIT membranes. Results: DIA heart

exhibited FR-induced damage to MIT indicated by ~ 17% (p<0.05) increase in oxidized Q10

but no considerable rise in CD formation in membrane lipids and expression of MIT eNOS as

well as decreased S3 and S4 O2 consumption, RCI and the rate of OP (all p<0.01). Further,

NFκB and MF were increased (both p<0.01), MP decreased (p<0.001), but the latter change

was associated with its increased stability. Linear regression analysis revealed significant

association (r=0.67; p<0.05) between the increase in MF and the decrease in MP in DIA MIT.

In contrast to healthy controls, DIA heart show increased expression of CA IX - a process

mediated. via the HIF-1 transcription factor. Conclusions: The relatively little oxidative

damage to membrane lipids, increase in NFκB and MF as well as in capability of the DIA

heart MIT to maintain MP and the upregulation of hypoxic genes, particularly that of CA IX,

all testify for active participation of EP processes in acute DIA heart. In the latter processes

FR are playing dual role. They are involved in damaging, but also in signaling towards

induction of EP mechanisms. Grants: VEGA SR 2/7126/27, 2/0173/08, APVV 51-027404, SP

51/0280901

52

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FEASIBILITY AND SAFETY OF INTRACORONARY INJECTION OF MESENCHYMAL STEM CELLS IN SEVERE ISCHEMIC CARDIOMYOPATHY. MMEDIATE, INTERMEDIATE, AND LONG-TERM FOLLOW-UP

,

edure. All others are alive, 3 of them in good clinical condition. Conclusion:

tracoronary application of MSC in severe ischemic cardiomyopathy is safe and feasible.

hanges at 12 weeks after the procedure are promising but more data are needed to evaluate

e efficacy and medical benefit of this technique.

I Eva Goncalvesova1, Jan Lakota2, Viliam Fridrich1, Pavol Povinec3, Milan Luknar1

Juraj Fabian1 1National Institute of Cardiovascular Disease, Bratislava, Slovakia, 2National Cancer Institute, Bratislava, Slovakia, 3Biont PET Centre, Bratislava, Slovakia

Introduction: Mesenchymal stem cells (MSC) have documented a potential of cardiac

regeneration in animal models. Data on use of MSC in humans are very rare. The main reason

for this is apprehension of myocardial infarction (MI) induction and undesirable

transformation of MSC. Aim: To evaluate safety and feasibility of intracoronary injection of

autologous MSC in patients with ischemic cardiomyopathy. Patients and methods: Ten heart

failure pts (all males, mean age 49.6 ± 4.8 years) with a history of MI and severe systolic

dysfunction (mean left ventricular ejection fraction (LVEF) 18.7 ± 7.6%) were included. In

five of them coronary angiography showed nonsignificant stenoses. Five others had coronary

lesions not suitable for any intervention. In 4 of all 10 pts. viable myocardium was detected

using SPECT thalium scintigraphy. 30 mL of bone marrow blood from the iliac crest was

obtained. The MSC (CD45, CD34, CD 117, CD38, CD71, CD3 negative; CD90, CD44,

CD13 positive) were isolated and expanded ex vivo. Coronary catheterization was performed

using an over-the-wire balloon catheter. Suspension of MSC was injected in four 3 ml boluses

during 3-minutes low pressure artery occlusions. Mean number of cells injected was 2.3 ±

1.0x10e7. NYHA class, six minutes walking distance (6mWD), peak oxygen consumption

(pVO2), left ventricular end diastolic diameter (LVdD), LVEF, wall motion score (WMS),

and brain natriuretic peptide (BNP) were evaluated before and 12 weeks after the procedure.

Mean follow-up time of the patients was 15 ± 6 months. Results: No clinical, ECG or

humoral signs of acute MI were observed. No symptomatic or significant dysrhythmias

occurred immediately after the procedure. After 12 weeks there was no significant change in

NYHA class, resting LVEF or WMS. Increase of 6mWD (421±112 vs 472±122 m, p=0.05)

and pVO2 (16.6± 3.2 vs 20.3±5.2ml/kg/min, p =0.02), and decrease of LVdD 63.5 ± 26.5 vs

59.5± 25.8 mm, p = 0.02), and BNP (532± 650 vs 359± 513 pg/ml, p=0.02) were recorded.

One patient underwent heart transplantation one year, 2 died suddenly 7 and 5 months, resp.,

after the proc

In

C

th

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SEXUAL DIMORPHISM IN FUNCTIONAL PROPERTIES OF CARDIAC NA,K-ATPASE IN SHR

1 1 1Veronika Javorkova , Jana Vlkovicova , Lucia Mezesova , Olga Pechanova2, Norbert

art Research, SAS, 2Institute of Normal and Pathological Physiology, Slovak Vrbjar1 1Institute for HeAcademy of Sciences, Bratislava, Slovakia.

The present study deals with investigation of functional properties of the cardiac Na,K-

ATPase in 16 weeks old male and female spontaneously hypertensive rats (SHR). The Na,K-

ATPase activity in the presence of increasing concentrations of ATP, as well as Na+ was

lower in SHR of both genders, as compared to respective normotensive controls. Evaluation

of kinetic parameters revealed a significant decrease of the maximum velocity (Vmax) in males

(30% for ATP-activation, 40% for Na+-activation), as well as in females (24% for ATP, 29%

for Na+), indicating a hypertension-induced diminution of the number of active enzyme

molecules in cardiac sarcolemma. The Michaelis-Menten constant (Km) remained unchanged

by hypertension in both genders. The concentration of sodium that gives half-maximal

reaction velocity (KNa), increased by 38% in male and by 70% in female SHR. This

deterioration in the affinity of the Na+-binding site together with decreased number of active

Na,K-ATPase molecules are probably responsible for the impaired enzyme function in hearts

of SHR. Direct comparison of SHR of both genders showed, that the enzyme from female

hearts seems to be adapted better to hypertension as documented by its increased activity as a

consequence of improved ability to bind and utilize ATP, as suggested by 32% decrease of

Km value in females. In addition, the enzyme from female hearts is able to increase its activity

(by 41%) in the presence of increasing sodium concentration even in the range where the

enzyme from male hearts is already saturated.

This study was supported by Slovak Grant Agencies (grant No. VEGA 2/7127/27 and APVV-

51-059505).

54

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PART II. ATORVASTATIN A D OMEGA-3 FATTY ACIDS DECREASE SUSCEP BILITY

IN-43 IMPLICATİON.

Vladimir Knezl2, Peter Weismann3, Ludmila kruhlicova1, Jan Jakubovsky, Narcis Tribulova1.

ent. Immunostaining of fibronectin was

ent. Cx43 immunopositivity was confined to intercalated disc-related gap

istar rats, while pronounced lateral (side-to-side) localization of Cx43

as demonstrated in hHTG rat heart ventricles. This abnormal pattern of distribution was not

liminated either by either omega-3 FA or atorvastatin. However, immunostaining of Cx43

as stronger in treated Wistar and hHTG rat hearts. Conclusions and implications: Results

howed clear-cut antifibrillating effects of both omega-3 FA and atorvastatin, while up-

gulation of Cx43 can be implicated. It is possible that treatment can modulate turnover

nd/or gene expression of Cx43 and this should be analyzed in further studies. This work was

N TOF HYPERTRIGLYCERIDEMİC RAT HEART TO LETHAL ARRHYTHMIAS. CONNEX

Lucia Kolenova, Katarina Dlugosova1, OFaculty of Medicine, Comenius University, Bratislava, 1Institute for Heart Research, SAS, Bratislava 2Institute of experimental Pharmacology SAS, , 3Department of Anatomy, Faculty of Medicine, Comenius University, Bratislava

Background and purpose: We have shown previously that hereditary hypertriglyceridemic

rats are prone to lethal arrhythmias, such as ventricular fibrillation (VF). Clinical studies

suggest that lipid-lowering drugs (statins) as well as omega-3 fatty acids (omega-3 FA)

reduce the incidence of cardiovascular diseases and sudden arrhythmic death. To elucidate the

possible cardioprotective/antiarrhythmic mechanisms we focused on intercellular channel

protein connexin-43 (Cx43), which is responsible for cell-to-cell electrical and metabolic

signals propagation. Experimental approach: Experiments were conducted on adult male

hereditary hypertriglyceridemic rats (hHTG) treated with atorvastain (0.05mg/100g b.w./day)

or fed with omega-3 FA (30mg/day) for 2 month. Myocardial expression and distribution of

Cx43 in left ventricles of treated and untreated hHTG rats was examined using cryostat

sections and immunolabeling of Cx43 with specific MAB (Chemicon, USA) followed by

quantitative image analysis. Immunohistochemistry of extracellular matrix protein,

fibronectin, was performed as well. VF inducibility was examined using Langendorff model

of isolated heart. Results showed that omega-3 FA reduced blood pressure and serum

triglycerides in hHTG rats at the same level as atorvastatin. VF inducibility was significantly

decreased due to atorvastatin or omega-3 FA treatm

moderately but significantly increased in hHTG compared to control Wistar rat heart,

regardless the treatm

junctions in control W

w

e

w

s

re

a

supported by APVV 51-059505.

55

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SEX DIFFERENCES IN THE INCIDENCE OF LETHAL ARRHYTHMIAS ORRELATE WITH MYOCARDIAL CONNEXIN-43 EXPRESSION DISPARATIES.

logy, Institute for Heart Research, SAS, Bratislava, Medical Faculty of Comenius University, Bratislava, Slovak Republic

ntified sex differences in incidence of

o-cell communication ensured by gap junction

C Vladimir Knezl, Jan Drimal, Marcela Mitasikova1, Peter Weismann2, Narcis Tribulova1

Institute of Experimental Pharmaco 1

2

Background: Clinical and experimental data have ide

cardiac diseases and/or lethal arrhythmias. The cellular mechanisms responsible for these

disparities are still not fully elucidated. Cell-t

conexin-43 (Cx43) channels plays a crucial role in myocardial tissue homeostasis and

synchronisation. Therefore, we hypothesized that expression and/or distribution of Cx43 may

differ between males and females. Aim of this study was to examine both myocardial Cx43

and susceptibility of the heart to life-threatening arrhythmia, ventricular fibrillation (VF), in

non-hypertensive and hypertensive male and female rats. Methods: Experiments were

conducted on aged (>1 year-old) male and female normotensive Wistar and spontaneously

hypertensive (SHR) rats. Ventricular tissue taken from excised hearts of anesthetized rats was

immediately frozen in liquid nitrogen and processed either for in situ immuno-detection or

Western-blotting of Cx43 using mouse MAB. Susceptibility to VF was examined in isolated

heart preparation according to Langendorff using either electrical burst stimulation or

hypokalemic perfusion. Key results: Both male and female SHR rats were more vulnerable to

VF compared to Wistar counterparts. In correlation, Western-blotting of Cx43 revealed

significantly lower ventricular Cx43 expression in hypertensive than normotensive rats. In

addition, all SHR hearts exhibited abnormal myocardial distribution of Cx43, i.e. enhanced

amount of lateral, side-to-side Cx43-positive gap junctions. Female rats, both SHR and Wistar

were significantly less susceptible to VF comparing to males counterparts. It correlated with

significantly higher Cx43 expression in female comparing to male rats. Conclusions: Taken

together these findings indicate that higher level of myocardial Cx43 expression is linked with

lower lethal arrhythmia susceptibility and vice versa. This fact can explain, at least in part,

sex-related differences in incidence of life-threatening arrhythmias. Supported by VEGA

2/6064/27 and APVV 51-059505, 51-017905 grants.

56

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PROTECTION AGAINST ISCHEMIA-INDUCED ARRHYTHMIAS IN THE DIABETIC HEART DOES NOT REQUIRE PI3K/AKT ACTIVATION: RELEVANCE TO ISCHEMIC PRECONDITIONING

Pharmacobiochem Lab, Fac Med

NAC 155 ± 15* 290 ± 52*

PC 195 ± 40* 88 ± 25* 77 ± 19* 151 ± 39*

<0.05 vs. non-PC control hearts conclusion, both, PC and D might induce adaptive processes in the myocardium lowering

usceptibility to antioxidant treatment. Reduced vulnerability to ischemic arrhythmias in

cutely D and preconditioned hearts does not require PI3K/Akt activation. Supported by grants

EGA SR 2/0173/08, APVV SK-CZ-0049-07 and GACR 305/07/0875

Jana Matejikova1, Jarmila Kucharska2, Jan Neckar3, Frantisek Kolar3, Dezider Pancza1, Tana Ravingerova1

21Inst Heart Res, Slovak Acad Sci & CEKVY SAS; Comenius Univ, Bratislava, SR; 3Inst Physiol, Acad Sci of the CR & Ctr Cardiovasc Res, Prague, CR Although clinical data have clearly demonstrated that diabetic patients are more prone to

ischemic heart disease, experimental data revealed controversies in response of the diabetic

(D) heart to ischemia/reperfusion (I/R). Higher tolerance to I/R injury in D heart might share

similar mechanisms with ischemic preconditioning in the normal heart, e.g., reactive oxygen

species (ROS) signaling and activation of pro-survival protein kinases. Aims were to explore

the role of phosphatidylinositol 3-kinase (PI3K)/Akt and ROS in susceptibility to ischemic

arrhythmias in hearts of 1-wk D rats (STZ 65 mg/kg, i.p.) and in normal hearts preconditioned

by 1 cycle of I/R (5 min each) before I/R. Our further goal was to characterize the effect of D

and PC on endogenous antioxidant systems. Langendorff-perfused hearts of D rats, non-

preconditioned (non-PC) and preconditioned (PC) hearts of normal rats were subjected to 30-

min occlusion of the LAD coronary artery with or without prior 15-min perfusion with

PI3K/Akt inhibitors wortmannin (W; 100 nM) and LY294002 (LY; 5 μM) or antioxidant N-

acetylcysteine (NAC; 4 mM). Levels of CoQ10, CoQ9 and α-tocopherol were measured in

left ventricular myocardium (HPLC). Total number of premature ventricular complexes

(PVC) monitored during the whole period of ischemia was significantly lower in D and PC

groups, as compared with non-PC controls (C), as well as in NAC- and LY-treated non-PC

groups. Antiarrhythmic effect in D and PC hearts was blunted by neither NAC nor PI3K/Akt

inhibition. Both, D and PC significantly increased levels of CoQ10, CoQ9 (D 19.6 ± 0.8 and

217.3 ± 9.5; PC 23 ± 2.2 and 250 ± 19 vs. 17.4 ± 0.5 and 185.0 ± 5.0 nmol/g, resp., in C;

P<0.05) and α-tocopherol (38.6 ± 0.7 and 40 ± 1 vs. 31.5 ± 2.1 nmol/g in C; P<0.01). Groups PVC (total number) C W non-PC 551 ± 61 480 ± 50

LY

D 220 ± 46* 181 ± 51* 251 ± 73* 207 ± 51*

*PIn

s

a

V

57

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CALCIUM SIGNALING TO RAT HEART MITOCHONDRIA IN ACUTE DIABETES: A MEASURE FOR SALVAGE OF CARDIAC ENERGETICS

1Jana Mujkosova , Michal Cagalinec2, Miroslav Ferko1, Olga Ulicna3, Iveta

ardiovasc. Sci., SAS, Int. Laser Ctr.; Lab. Pharmacobiohem,

ation

1.) Ziegelhőffer A. et. al., Ann NY Acad Sci 967, 1-7, 2002; 2.) Waczulikova I. et al., Can J

Physiol Pharmacol 85, 372-81, 2007. Support: 2/0173/08, 2/7126/27, 1/3037/06, 1/3442/06

/2007.

Waczulikova4, Dana Kincelova4, Tana Ravingerova1, Attila Ziegelhőffer1

1Inst. Heart Res., Ctr. Excel. C 2 3

3rd Dpt. Inter. Med., Fac. Med., 4Dpt. of Nuclear Phys. and Biophys., Fac. Math., Phys., Inf., Comenius Univ., Bratislava, Slovakia

Background: Due to abnormal intracellular Ca sequestration by sarcoplasmic reticulum and

mitochondria (MIT), diabetic (DIA) heart (H) cells become strong exposed to calcium. This is

manifested by prolonged Ca-transients and by increased Ca-driven energy consumption.

However, these alterations are also accompanied with decreased trans-sarcolemmal influx of

Ca and enhanced formation of energy channels (ECH) in membranes of H MIT which yield in

partial adaptation to DIA. This indicates that measurements of physical parameters of

membranes might provide valuable additional information about capability of the H to adapt

to and cope with DIA. The present study is focused to elucidation of mutual quantitave

relationships among membrane fluidity (MF), trans-membrane potential (MP), and calcium

movements in H cells in respect to the amplitude of calcium transient (ACT) in acute DIA H.

Experimental: Adult male Wistar rats, 220±15 g b.wt.; were kept in 12L/12D regimen (22 oC) on standard pellet diet with water ad libitum. DIA was induced by streptozotocin (STZ)

65mg/kg b.wt., i.p. Experiment was terminated on the day 8 after STZ by cervical dislocation.

For control of the metabolic state of animals see (1). For cardiomyocytes, MIT preparations

and biophysical parameters see (2). Results and Discussion: MIT from DIA H exhibited

descendent MP and increased MF (p>0.05) - the latter phenomenon associated with

augmented energy transduction from MIT via an increase in number of the ECH. A

Significant negative association between MF an MP in DIA H MIT (p<0.05; r=0.67) and an

increase in ACT were also found (p=0.08). Conclusions: Prolonged duration and increased

ACT regulate the capacity of ATP delivery through the MIT membrane of DIA H. Form

of MIT ECH is coupled with decreasing of MF and MP of DIA H MIT.

APVT 51-027404, UK/399

58

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EFFECT OF CHRONIC SOCIAL STRESS ON BLOOD PRESSURE AND NEUROGENIC CONTRACTIONS OF MESENTERIC ARTERY IN RATS WITH

ENETIC HYPERTENSION

he aim of this study was to investigate the effect of 8-week-lasting social stress on blood

m activity. Provinol

ese results suggest that inhibition of sympathetic activity in

ascular system of hypertensive rats exposed to crowding stress may serve as protective

echanism against marked increase of blood pressure.

upported by grants VEGA No.2/6150/27, 2/7064/27 and APVT-51-018004.

G Jozef Torok , Angelika Puzserova , Anna Zemancikova , Iveta Bernatova Institute of Normal and Pathological Physiology, Slovak Academy of Sciences and Centrum of Experimental Medicine, Bratislava, Slovak Republic T

pressure and contractile responses of isolated superior mesenteric artery to adrenergic stimuli

in normotensive Wistar, borderline hypertensive (BHR, offspring of spontaneously

hypertensive dams and Wistar sires) and spontaneously hypertensive rats (SHR). Experiments

were performed on adult 12-week-old males, which were in each phenotype randomly divided

into six groups: a/ control rats kept in groups of 4 rats/cage (480 cm2/rat); b/ stressed group (5

rats/cage, 200 cm2/rat), c/ group treated with provinol (20 mg/kg/day, 480 cm2/rat); d/ stressed

group treated with provinol (20 mg/kg/day, 200 cm2/rat); e/ group treated with low dose of

nitric oxide (NO) synthase inhibitor L-NAME (1.5 mg/kg/day, 480 cm2/rat); f/ stressed group

treated with L-NAME (1.5 mg/kg/day, 200 cm2/rat) for 8 weeks. Stress was produced by

exposure of rats to 8-week crowding with living space reduced to 200 cm2/rat. Blood pressure

was measured by tail-cuff plethysmography. Rings of isolated superior mesenteric artery were

mounted in organ baths for measurements of isometric contractile force. Neurogenic

contractions of mesenteric artery were elicited by electrical stimulation of perivascular nerves.

Social stress increased blood pressure in SHR (by 11%) and BHR (by 10%), as well as in L-

NAME-treated SHR (by 12%) and BHR (by 11%) but no differences in blood pressure were

observed in normotensive Wistar rats. Social stress did not influence contractions of

mesenteric artery to exogenous noradrenaline in all three phenotypes. However, the

magnitude of neurogenic contractions induced by endogenous noradrenaline was significantly

reduced in the mesenteric artery from stressed SHR and, at least in part, in stressed BHR. In

L-NAME-treated SHR and BHR, the decreased reactivity of mesenteric artery was restored,

suggesting that this hyporeactivity is due to an increase in the NO syste

did not influence contractions induced by exogenous noradrenaline in any of used three

phenotypes, but it reduced neurogenic contractions of mesenteric artery in control Wistar and

BHR rats and in stressed SHR. Th

v

m

S

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Page 60: Program Book of Abstracts - SAV · 10.00 - 10.20 Zoltan Papp, Debrecen (Hungary) Altered contractile protein phosphorylation during heart failure 10.20 - 10.35 Andrej Dukat, Bratislava

REGULATION OF CARDIAC NA,K-ATPASE BY NITRIC OXIDE DURING HYPERTENSION

1Jana Vlkovicova , Veronika Javorkova1, Lucia Mezesova1, Olga Pechanova2, Norbert

Vrbjar1 1Institute for Heart Research, SAS, 2Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovakia.

The Na,K-ATPase was hypothesized to be involved in development of systemic vascular

hypertension through its effects on smooth muscle reactivity and myocardial contractility. Our

study deals with the regulatory role of nitric oxide (NO) on functional properties of the

cardiac Na,K-ATPase in three various animal models of hypertension. The first group was

represented by spontaneously hypertensive male rats (SHR) with increased activity of NO-

synthase by 60% (Sh1). The second group of SHR revealed a decreased activity of NO-

synthase by 40% (Sh2). In the third model (LN), the hypertension was induced by

administration of an inhibitor of NO-synthase, L-NAME (40mg.kg-1.day-1) resulting in

depression of NO synthesis by 72%. Studying the utilization of energy substrate ATP we

observed higher Na,K-ATPase activity in the whole concentration range of ATP for the group

Sh1. On the other hand, the Na,K-ATPase activity was depressed in Sh2 and LN groups.

Evaluation of kinetic parameters revealed increased value of Vmax by 37% and increased

affinity of the ATP binding site as indicated by the lowered Km value by 38% in group Sh1. In

the Sh2 and LN groups the Vmax was decreased by 30% and 17% respectively with no

significant change of Km value as compared to controls. During the activation with Na+ we

observed a stimulation mainly in the presence of higher concentrations of cofactor yielding

increased Vmax by 64% and increased KNa by 106% in the group Sh1. In group Sh2 we found

decreased activity in whole concentration range of NaCl resulting in decreased Vmax by 40%

and increased KNa by 38%. In the LN group the enzyme activity was significantly depressed

at lower concentrations of NaCl, showing unchanged Vmax with increased KNa by 50%. The

above data indicate a positive role of increased NO-synthesis in improvement of utilization of

ATP as well as enhanced binding of Na+ by the cardiac Na,K-ATPase. Thus the intensity of

NO synthesis may be a determining factor in regulating the functional properties of the

cardiac Na,K-ATPase.

This study was supported by Slovak Grant Agencies (grant No. VEGA 2/7127/27 and APVV-

51-059505).

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PROTECTIVE EFFECTS OF TREATMENT WITH SIMVASTATIN AGAINST ISCHEMIA/REPERFUSION INJURY IN ISOLATED RAT HEART

ova

t of Pharmacology and Toxicology, Faculty of harmacy, Comenius University, Bratislava, Slovak Republic

Maria Zazrivcova1, Adriana Adameova2, Dezider Pancza1, Jan Styk1, Tana Ravinger 1

1Institute for Heart Research and Centre of Excellence for Cardiovascular Research of the Slovak Academy of Sciences, 2DepartmenP The inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA)

reductase, which is required for cholesterol (CH) biosynthesis, or statins, are most frequently

prescribed drugs used in the primary and secondary prevention of coronary artery disease by

lowering serum levels of CH. However, statins are also known to have additional, so called

pleiotropic activity, since inhibition of HMG-CoA reductase not only prevents the synthesis

of CH, but also modulates the synthesis of other important molecules. We have previously

shown protective effects of simvastatin (S) on ischemia/reperfusion (I/R) injury in rats with

high levels of CH. The aims of the present study were to investigate the effect of treatment

with S on I/R injury in rats with normal levels of CH. Male Wistar rats were treated with

simvastatin (10 mg/kg/day, p.o.). After 5 days, experiments were performed in Langendorff-

perfused isolated hearts of S-treated rats and control non-treated animals (C). Regional

(occlusion of LAD coronary artery) or global ischemia lasted 30 min and was followed by 40-

min reperfusion. We measured ventricular arrhytmias during ischemia and 10 min of

reperfusion and recovery of contractile function (LVDP) at the end of experiment. In the S

group, the total number of ventricular premature beats during ischemia was reduced to 162 ±

62 (vs. 551 ± 61 in C; P<0.05). The total duration of the episodes of ventricular tachycardia

was significantly shorter (9.5 ± 4.1 s vs. 43.6 ± 8.6 s in C; P<0.05). In addition, severity of

reperfusion-induced arrhythmias was lower (arrhythmia severity score 2.5 ± 0.3 vs. 4.4 ± 0.5

in C; P<0.05). LVDP recovery was increased by 37.5% in the S-treated group. In conclusion,

treatment with S may confer an efficient protection against I/R injury independent of its lipid-

lowering activity. Supported by grants VEGA SR 2/0173/08, 1/4296/07

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LIST OF PARTICIPANTS e-m l p.

a (Canada) [email protected] 33

du.pl 45 alentin Both (Slovakia)

59 arcis Tribulova (Slovakia) [email protected] 32,45,47,49,51,55,56

a Turan (Turkey) [email protected] 18 gnes Vegh (Hungary) [email protected] 26

ana Vlkovicova (Slovakia) [email protected] 27,60 lovakia) [email protected] 27,54,60

aria Zazrivcova (Slovakia) [email protected] 61 ttila Ziegelhoffer (Slovakia) [email protected] 31,52,58

aiMadhu Anand-Srivastava (Canada) [email protected] 21 Amarjit S. ArnejBarbara Bacova (Slovakia) 49 Monika Bartekova (Slovakia) [email protected] 50 Andrzej Beresewicz (Poland) [email protected] P. Czubryt (Canada) [email protected] 29 Dipak K. Das (USA) [email protected] 46 Naranjan S. Dhalla (Canada) [email protected] 38 Katarina Dlugosova (Slovakia) [email protected] 49,51,55 Andrej Dukat (Slovakia) [email protected] 40 Miroslav Ferko (Slovakia) [email protected] 31,52,58 Eva Goncalvesova (Slovakia) [email protected] 41,53 Veronika Javorkova (Slovakia) [email protected] 27,54 Philip K. Kadowitz (USA) [email protected] 23 LorrieA. Kirshenbaum (Canada) [email protected] 44 Frans H.H. Leenen (Canada) [email protected] 19 Milan Luknar (Slovakia) [email protected] 41,53 Vladimir Knezl (Slovakia) 55,56 Lucia Kolenova (Slovakia) 55 Jana Matejikova (Slovakia) [email protected] 57 Nilanjana Maulik (USA) [email protected] 12 Dennis B.McNamara (USA) [email protected] 14 Jana Mujkosova (Slovakia) [email protected] 31,52,58 Jan Murin (Slovakia) [email protected] 37 Marie Novakova (Czech Republic) [email protected] 30 Grant Pierce (Canada) [email protected] 13 Jan Styk (Slovakia) [email protected] 50,61 Ludmila Okruhlicova (Slovakia) [email protected] 34,47,49,51,55 Zoltan Papp (Hungary) [email protected] 39 Olga Pechanova (Slovakia) [email protected] 24,27,54,60 Tana Ravingerova (Slovakia) [email protected] 16,31,50,52,57,58,61 Stephen W. Schaffer (USA) [email protected] 15 Pawan K. Singal (Canada) [email protected] 36,47 Jan Slezak (Slovakia) [email protected] 36,47 Ashok Srivastava (Canada) [email protected] 25 Jozef Torok (Slovakia) [email protected] NBelmAJNorbert Vrbjar (SMA

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