Effects of intra-arterial infusion of prostaglandin E1 on gastric secretion and blood flow.

The effect of intra-arterial infusion of Prostaglandin E1 (PGE1) on gastrict total and mucosal blood flow and acid secretion was studied in an exteriorized, chambered preparation of canine fundic stomach. Total gastric blood flow was measured simultaneously by venous outflow and by gamma-labeled microspheres. Mucosal blood flow also was measured by microspheres. Intra-arterial infusion of PGE1 at 1.0 microgram/min completely inhibited histamine-stimulated acid secretion. This inhibition was accompanied by a significant increase in both total (p less than 0.01) and mucosal blood flow (p less than 0.01). The ratio of mucosal to total blood flow remained unchanged during histamine stimulation (78 +/- 4%) and PGE1 inhibition (79 +/- 4%). The results suggest that inhibition of acid secretion can occur in the face of increased blood flow. This observation is contrary to the generally accepted concept that inhibition of acid secretion always is associated with a decrease is mucosal blood flow.