Effect of indomethacin on gastric mucosal prostaglandins in humans. Correlation with mucosal damage.

We evaluated in healthy human beings the effect of indomethacin on gastric mucosal prostaglandin concentration and on gastric mucosal damage in a placebo-controlled study. Prostaglandin E2, prostaglandin F2 alpha, and 6-keto prostaglandin F1 alpha concentrations of gastric mucosal biopsy specimens, obtained endoscopically, were measured by radioimmunoassay. Mean prostaglandin concentration of the antrum and fundus was similar. In both regions there was considerable intersubject variability in prostaglandin concentration. Repeated 50-mg oral doses of indomethacin for 4 days reduced mean prostaglandin F2 alpha and E2 concentration by 50.2% and 69.4%, respectively, in the fundus and by 40.0% and 49.7% in the antrum, but this led to no significant mucosal damage when assessed endoscopically or histologically. A single 100-mg oral dose of indomethacin reduced mean prostaglandin F2 alpha and prostaglandin E2 concentration by 81.4% and 60.9% in the fundus and by 64.2% and 57.5% in the antrum and also induced significant mucosal injury in both regions when assessed endoscopically. However, there was no correlation between degree of suppression of prostaglandin concentration by indomethacin and endoscopic evidence of mucosal damage.