The effect of prostaglandin E2, 15-methyl prostaglandin E2, and metiamide on established canine gastric mucosal barrier damage.

The ability of two types of gastric acid inhibitor to reverse established gastric mucosal barrier damage was studied in canine Heidenhain pouches. A model of established barrier damage was prepared and validated by perfusing Heidenhain pouches with an acid saline solution containing 20 mmoles of aspirin for 2 hours (damage period) and then perfusing with acid saline alone for a third hour (recovery period). Increases in gastric mucosal permeability to H+ and Na+ produced in the damage period still were present and were significant in the recovery period. In subsequent experiments the effect of topically applied prostaglandin E2 and 15-methyl prostaglandin E2 and intravenously administered prostaglandin E2, 15-methyl prostaglandin E2, and Metiamide on the recovery period permeability was studied. Topical application of the prostaglandins and intravenous Metiamide had no effect on the increased permeability. Intravenously administered prostaglandins returned the permeability to normal and therefore reversed established barrier damage. This effect may have important therapeutic implications in acute gastric mucosal lesions.