Abstract: | It has been shown previously that trypsinogen and its activation peptide but not trypsin decreased gastric secretion. The purpose of this work was to study the dose-action relation between the intraduodenal infusion of trypsinogen and gastric secretion. Three dogs provided with gastric and duodenal Thomas fistulae were stimulated by continuous i.v. perfusion of porcine gastrin I-II (6 microgram kg-1 h-1). Pancreatic juice was diverted to the exterior and gastric secretion was collected. Upon reaching a gastric secretory plateau, porcine trypsinogen was infused intraduodenally at doses of 5, 10, 20, 40, 80 and 160 mg. Each test was continued for a further 60 min. Control was made with isotonic saline. There was a dose-related inhibition of the gastrin-stimulated gastric acid output. This inhibition reached a maximum of 50% with 40 mg of intraduodenal trypsinogen, showing no increase with higher doses. |