Effect of bulbar acidification on basal secretion of acid and gastrin in dog.

Dogs were provided with mucosal septal pouches of the stomach and of the duodenal bulb. In some dogs a drainage gastric cannula was inserted into the most dependent portion of the stomach. In dogs which were found to secrete acid spontaneously during a control period at the start of each experiment, the bulbar puches were perfused with 0.1 M HC1 for 5-120 min. Bulbar acidification rapidly and profoundly reduced the basal acid output. In dogs which did not secrete acid spontaneously during the control periodbulbar pouches were perfused with 0.1 M HC1 for 1 h. Bulbar acidification did not significantly influence the plasma gastrin concentration and no acid was secreted from the Pavlov pouches following such acidification. The present results support the hypothesis that reduction of the intrabulbar pH may contribute to the reduction of acid secretion during interdigestive periods. The physiological significance of of mechanisms in the upper intestine which induce acid secretion following a reduction of the intraluminal pH is questioned.