Comparative effects of amylin and cholecystokinin on food intake and gastric emptying in rats

CCK is a physiological inhibitor of gastric emptying and food intake. The p ancreatic peptide amylin exerts similar actions, yet its physiological impo rtance is uncertain. Objectives were to compare the dose-dependent effects of intravenous infusion of amylin and CCK-8 on gastric emptying and food in take in rats, and to assess whether physiological doses of amylin are effec tive. Amylin and CCK-8 inhibited gastric emptying with mean effective doses (ED(50)s) of 3 and 35 pmol.kg(-1).min(-1) and maximal inhibitions of 60 an d 65%, respectively. Amylin and CCK-8 inhibited food intake with ED(50)s of 8 and 14 pmol.kg(-1).min(-1) and maximal inhibitions of 78 and 69%, respec tively. The minimal effective amylin dose for each effect was 1 pmol.kg(-1) .min(-1). Our previous work suggests that this dose increases plasma amylin by an amount comparable to that produced by a meal. These results support the hypothesis that amylin acts as a hormonal signal to the brain to inhibi t gastric emptying and food intake and that amylin produces satiety in part through inhibition of gastric emptying.