Stimulatory effects of bombesin on plasma trypsin release and exocrine pancreatic secretion in dogs.

We examined the effect of bombesin on plasma trypsin release and exocrine pancreatic secretion in dogs. Bombesin significantly increased plasma immunoreactive trypsin (IRT). Atropine significantly inhibited the response of plasma IRT to bombesin. Pancreatic trypsin secretion was also increased by bombesin, as well as bicarbonate and protein outputs. Atropine failed to inhibit pancreatic trypsin secretion. In conclusion, bombesin has a stimulatory effect on plasma trypsin release mediated by a cholinergic mechanism and different from pancreatic secretion.