Effect of intravenous C-terminal octapeptide of cholecystokinin and intraduodenal ricinoleic acid on contractile activity of the dog intestine.

Intraduodenal infusion of ricinoleic acid and iv bolus injection of the C-terminal octapeptide of cholecystokinin produce markedly similar alterations in the digestive contractile patterns of the GI tract of the unanesthetized dog. The brief, initial stimulation of contractile activity in the proximal small intestine following both procedures is mediated through a cholinergic mechanism. The stimulatory response is followed by an inhibition of digestive contractile activity of unknown origin. These observations suggest that possibility that the GI hormone, cholecystokinin, may mediate the intestinal motor response evoked by infusion of ricinoleic acid directly into the proximal small intestine.