PEPTIDE CHOLESYSTOKININ RECEPTOR ANTAGONIST INCREASES FOOD-INTAKE IN RATS

An analogue of the C-terminal heptapeptide of cholecystokinin (CCK) r( SO3-)-Nle-Gly-D-Trp-Nle-Asp-a-2-phenylethylester is a potent, specific CCK receptor antagonist. Intraperitoneal injection of the antagonist abolished suppression of real feeding and sham feeding by exogenous CC K-8 (1.8 nmol/kg), and significantly increased real feeding. Assuming an antagonist distribution like that of exogenous CCK-8, our results s uggest that exogenous CCK-8 and endogenous CCK reduce food intake by a cting at a site(s) accessible to peripherally administered peptides.