Pancreatic polypeptide and vagal stimulation of gastric and pancreatic secretion in dogs.

In four dogs provided with pancreatic, gastric, and esophageal fistulae, the effects of bovine pancreatic polypeptide (BPP) infused at a physiological dose level (240 pmol per kg/hr) on gastric and pancreatic responses to sham-feeding were studied. The maximal gastric and pancreatic secretion was produced by pentagastrin and secretin, and OP-CCK infusion, respectively, with or without additions of BBP. Exogenous BPP did not change gastric acid and pepsin outputs stimulated by pentagastrin or sham-feeding, but significantly inhibited basal and maximally stimulated pancreatic protein secretion. The peak pancreatic protein, but not bicarbonate response to sham-feeding was reduced by about 31% by BPP. This reduction by BPP amounted to about 57% when the pancreas was stimulated maximally by OP-CCK. It is concluded the PP released by cephalic-vagal excitation does not affect gastric secretion, but inhibits pancreatic protein secretion, and thus might contribute to the lower pancreatic response to sham-feeding as compared with that produced by exogenous stimulants such as secretin and OP-CCK.