Vagal influences on the pancreatic response to intraluminal trypsin

The significance of vagal influences on the pancreatic response to intraluminal trypsin was investigated in conscious rats surgically prepared with bile-pancreatic fistulae. Vagotomy as well as cholinergic blockage depressed the hypersecretion of protein in fistula rats. Contrary to in control rats intraduodenal trypsin infusion did not change the protein output after vagotomy or cholinergic blockage. Indirect vagal stimulation induced by insulin hypoglycemia did not further increase the protein output in rats with their bile-pancreatic juice deviated from the intestine. In these latter rats, however, intraduodenal infusion of trypsin markedly inhibited the protein secretion. The results suggest that vagal integrity is essential for the response of the pancreas to intraduodenal trypsin.