Effect of glucagon on pentagastrin-stimulated gastric acid secretion and mucosal blood flow in cats.

The effect of glucagon given intravenously on pentagastrin-stimulated gastric acid secretion and gastric mucosal blood flow was studied in anaesthetized cats with gastric fistula. In parallel the catecholamines content in the gastric mucosa was measured. A continuous infusion of glucagon (25 ng/kg/h) caused a significant decrease of acid output (on the average by 33%) and gastric mucosal blood flow (by 40%). In these studies a concomitant increase in noradrenaline content of gastric mucosa was always seen (on the average by 108%). By determining the change in the ratio of blood flow to secretory rate a reduction in mucosal blood flow was found to be primary to the fall in secretion. The studies indicate that the inhibitory effect of glucagon on pentagastrin-stimulated acid secretion is due to restriction of mucosal blood flow. The results confirm also earlier data that glucagon stimulates the release of catecholamines.