Cyclic changes of plasma pancreatic polypeptide and pancreatic secretion in fasting dogs.

Fasting conscious dogs, each with a gastric fistula, Heidenhain pouch and Thomas duodenal fistula, were used. Basal pancreatic secretion showed periodic increases in phase with the periodic contraction of the stomach and duodenum. Periodic increases of plasma pancreatic polypeptide (PP), but not of gastrin, were observed in phase with the periodic contraction and secretion of the gut. Ganglion blockade abolished the cyclical activity, both secretory and motor, of the gut and of plasma PP. Intraduodenal infusion of lidocaine suppressed the spontaneous increase of pancreatic secretion and plasma PP. It is concluded both that the cyclical release of PP and the increase in pancreatic secretion are under the control of the intrinsic nerves of the duodenum.