Effect of some novel synthetic analogues of CCK-4 on insulin and glucagon secretion

Summary The biologic activities of three synthetic analogues of CCK-4 (Trp-Met-Asp-Phe-NH₂) in which (i) the C-terminal residue Phe was N-methylated (peptide I); (ii) the C-terminal Phe residue was N-methylated and Ser is substituted for Met in position 2 (peptide II); (iii) Pro was substituted for Trp in position 1 and the C-terminal amino nitrogen was methylated (peptide III), have been described. Peptides I and II have been found to inhibit the release of both insulin and glucagon, while peptide III was found to be a potent releasing agent for insulin and an inhibitor for glucagon. C.D.R.I. Communication n^o 4264. Abbreviations for amino acids and peptide derivatives according to IUPAC-IUB Commission on Biochemical Nomenclature [Biochemistry (Wash.)11, 1726, 1972].