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.