PANCREATIC-POLYPEPTIDE STIMULATES GASTRIC-MOTILITY THROUGH A VAGAL-DEPENDENT MECHANISM IN RATS

The present study examined the influence of peripherally administered pancreatic polypeptide (PP) on vagal control of gastric motility. The jugular vein was cannulated in urethane-anesthetized rats and a strain gauge was sewn onto the antrum to monitor motility. Intravenous infus ion of rat PP (2-200 pmol over 45 min) resulted in a dose-dependent in crease in antral contraction amplitude. The motility response to i.v. PP was eliminated by pretreatment with atropine or bilateral vagotomy. In contrast to i.v. infusion, close intra-arterial infusion of PP int o the gastric circulation had no effect on motility suggesting that PP does not act upon peripheral afferent terminals or directly within th e stomach. These results support the hypothesis that circulating PP in directly enhances gastric motility through a vagal cholinergic mechani sm.