Effect of Glucagon on Histamine- and Pentagastrin-Stimulated Canine Gastric Acid Secretion and Mucosal Blood Flow

Abstract

The effect of glucagon given intravenously, on histamine- and pentagastrin-stimulated gastric secretion, was studied in conscious dogs with Heidenhain pouches. The possible role that the gastric microcirculation may have in mediating the glucagon effect was assessed using the aminopyrine clearance technique. During maximal or submaximal histamine stimulation, glucagon, in dosages varying between 20 to 80 pg per kg failed to affect gastric secretion significantly. Pentagastrin-stimulated secretion was decreased as much as 90% from control levels by doses of glucagon ranging between 1 and 80 pg per kg. In these studies, a concomitant decrease in mucosal blood flow was always seen; however, by determining the change in the ratio of blood flow to secretory rate, the reduction in mucosal blood flow was found to be secondary to a fall in secretion. These studies indicate that glucagon has an inhibitory action on pentagastrin-stimulated secretion and that the inhibitory effect is not due to restriction of mucosal blood flow.