two tetrapeptides , glp-met-asp-phe-nh2 ( i ) and pro-met-asp-phe-nh2 ( ii ) , analogous to the c-terminal tetrapeptide amide of cholecystokinin ( cck-4 ) have been synthesized and their effect on the release of insulin from the isolated langerhans islets of rat pancreas compared with that of synthetic cck-4 .
C0021641
insulin
C0022131
langerhans islets of