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extension at the N-terminus; theoretically, therefore, it should possess full glucagon bioactivity. Peak II GLI was also identi- fied by chromatography of human plasma, and peak II GLI may consequently be an important glucagon-like hormone.

PORCINE GLICENTIN: PRESENT STATUS. A.J.Moody, K.Damm JCrgensen,L.Thim and K.H. Wolffbrandt. Novo Research Institute, Bagsvmrd, Denmark.

Porcine glicentin (gut GLI-]) consists of 69 amino acids with the sequence of glucagon as residues 33-61. Apeptide known as glicentiJ related pancreatic peptide (GRPP) has been isolated from porcine pancreas and shown to be identical with glicentin 1-30(I). This peptide has full molar reactivity with anti-glicentin serum R64 and is probably the peptide present in the halo of the A-cell secretory granules which is co-secreted with glucagon by the perfused porcine pancreas. The sequence of glicentin can be written as: GRPP.Lys.Arg. Glucagon. Lys.Arg.Hexapeptide. The bracketing of the glucagon moiety by Lys.Arg and the isolation of GRPP from the pancreas indicate that glicentin is probably very closely related to porcine proglucagon. The presence of glicentin in the intestine, and of the split products of glicentin in the pancrea% result in glicentin ( and perhaps glicentin 33-69 or oxyntomodulin) being released from the intestine by oral loads whereas GRPP ( and perhaps hexapeptide) are co-secreted with glucagon. The biological consequences of this secretory pattern are not yet known. To date it has been shown that glicentin reduces pentagastrin stimulated gastric acid secretion in the rat (2), suggesting that glicentin is a candidate enterogastrone. It is concluded that the sequence of glicentin is commensurate with it being proglucagon and that the effects of glicentin on gastric acid secretion indicate that it might be involved in the control of gastro-intestinal function. I) Thim,L. and Moody,A.J.: Biochim. Biophys. Acta , in press. 2) Kirkegaard,P., Moody,A.J., Holst,J.J., Loud,F.B.,

Sk~rv O l s e n , P . and C h r i s i a n s e n , J . : N a t u r e , i n p r e s s .

DISTRIBUTION AND MOLECULAR FORMS OF BOMBESIN AND GLUCAGON-LIKE

IMMUNOREACTIVITIES IN HUMAN BRAIN. M A Ghatei, L O Uttenthal, *H Langevin,

*M Rossor & S R Bloom, Department of Medicine, Royal Postgraduate Medical School, London, UK and *MRC Neuropharmacology Unit, Cambridge, UK.

The mammalian counterparts of the amphibian peptide bombesin have been found to be distributed throughout the brain, gastrointestinal tract and lung by immunological methods, but bombesin-like immunoreactivity (BLI) has not hitherto been mapped in the human brain. The position of glucagon as a

gut-brain peptide is less well established, and although glucagon-like immunoreactivities (GLI) have been mapped in brains of dog and rat, only

two human brains have previously been examined. We have determined the quantitative distribution of BLI and GLI by radioimmunoassay and gel filtration of extracts from 24 areas of 5 human brains obtained at autopsy from patients without demonstrable CNS pathology. The tissues were extracted with 0.5M acetic acid at 100oC and assayed by a bombesin radioimmunoassay crossreacting fully with gastrin-releasing peptide (GRP), and by an N-terminal to mid-molecule directed glucagon radioimmunoassay. The highest concentrations of BLI (pmol/g tissue, mean ± SEM) were found in