Effect of natural peptide YY on pancreatic secretion and cholecystokinin release in conscious dogs.

The effects of natural peptide YY on pancreatic secretion under different stimulatory conditions and on fatty acid-induced cholecystokinin release were examined in five conscious dogs with pancreatic and gastric fistulas. Intravenous infusion of natural peptide YY at 1 and 0.2 microgram/kg/hr caused 60 and 40% inhibition of secretin- and cholecystokinin-stimulated secretion, respectively, and 40-50 and 20-40% inhibition of intraduodenal oleate stimulated secretion, respectively. A significant but transient decrease in the plasma cholecystokinin level was observed in response to peptide YY under oleate stimulation. The present study demonstrates that peptide YY has a potent inhibitory effect on both exogenously and endogenously stimulated pancreatic secretion and has a mild suppressive effect on fatty acid-induced cholecystokinin release suggesting that this peptide is an important colonic inhibitor of pancreatic secretion.