Release of avian pancreatic polypeptide by various intraluminal contents in the stomach, duodenum, or ileum of turkeys.

Pancreatic polypeptide (PP) has been shown to be released postprandially in several species. In this study we tested the efficacy of an amino acid solution (905 mOsM), 0.1 N HCl (300 mOsM), 905 mOsM NaCl, 300 mOsM glucose, corn oil, and balloon distention within the stomach, duodenum, or ileum in stimulating release of avian PP (APP) in turkeys. Although they differ in osmolarity, and are thus difficult to compare, amino acids appeared to be the best stimulant and HCl the next best. The stomach was the site in which nutrients were most likely to stimulate APP release. There was no significant difference between the responsiveness of the the ileum and duodenum. A control experiment in which blood was drawn but no intraluminal treatments were administered indicated that handling and bleeding caused depression of normal fasting plasma [APP].