Effect of prostaglandin E2 on gastric mucosal bleeding caused by aspirin

The effect of prostaglandin E₂ on gastric mucosal bleeding caused by aspirin was studied. Blood in serial gastric washings was measured chemically for 30 min. Normal blood loss was equivalent to 0.05 ml/day. Aspirin, 600 mg four times daily, increased gastric bleeding on day 1; bleeding was further increased on day 2. On day 2, ingestion of 0.5 mg of prostaglandin E₂ 15 min before 600 mg of aspirin reduced the gastric microbleeding caused by aspirin. Prostaglandin E₂, 0.5 mg four times daily, did not change the normal blood loss. No consistent changes in gastric emptying or in secretion of chloride were detected.This work was supported in part by a grant from The Upjohn Company, Kalamazoo, Michigan.