Effect of glucagon on pentagastrin-induced gastric acid secretion and mucosal blood flow in the dog.

A steady state gastric acid secretion in dogs with both Heidenhain pouch and gastric fistula was maintained by continuous intravenous infusion of pentagastrin, 6 pg per kg-hr. The secretory rate, hydrogen ion concentration, acid output, and the clearance of aminopyrine from the plasma to the gastric lumen were significantly decreased for 2 to 3 hr in both the pouch and the gastric fistula by injection of glucagon, 50 pg per kg subcutaneously. The correlations between percentage changes in acid output and clearance of aminopyrine and between secretory rates and clearance of aminopyrine were both high. However, the ratio of aminopyrine concentration in the gastric juice to that in the plasma was increased significantly by glucagon in both the pouch and the gastric fistula. Thus, it is unlikely that the primary effect of glucagon on gastric inhibition is due to its influence on mucosal blood flow. The possibility that glucagon may have a direct effect on the acid-producing cells is suggested.