Effect of acid infusion into various levels of the intestine on gastric and pancreatic secretion in the cat.

Intraduodenal infusion of increasing amounts of hydrochloric acid solution results in a stepwise increase in the volume of pancreatic secretion and output of bicarbonate, reaching about 90% of amounts attained with exogenous secretin infused intravenously in increasing doses. Acid infusion into the different regions of the intestine stimulates pancreatic secretion only from the duodenum and upper jejunum, suggesting that the area of endogenous release of secretin by acid is confined to the upper part of the small bowel in the cat. Gastric acid secretion induced by pentagastrin, but not by histamine, is inhibited by acid perfusion of the duodenum. The acidification of other parts of the small intestine does not result in any change in gastric acid secretion induced either by pentagastrin or by histamine.