Mechanism of aspirin injury to human gastroduodenal mucosa.

The effect of oral plain aspirin tablets (ASA) on gastric mucosal endoscopic appearance and histology and on the prostaglandin E (PGE) content of the gastric juice and gastroduodenal mucosa was determined in ten healthy young adults. In all subjects the initial endoscopic appearances and microscopy of biopsies from antrum and duodenum were entirely normal. After ASA (2.6 g/day for 5 days) all subjects showed obvious endoscopic damage and 6 showed a histological gastric lesion consisting of loss of mucus and an alteration in nuclear appearance. In addition there was a significant reduction (p less than 0.01) in the PGE content of the gastric juice and of the antral and duodenal mucosa. There was no correlation between the severity of the mucosal damage and the degree of reduction in PGE. It is concluded that aspirin damages the human gastric mucosa by at least two distinct mechanisms one of which is inhibition of protective prostaglandins.