Effect of water-immersion stress on prostaglandin E2 in rat gastric mucosa.

We investigated the effect of stress on the prostaglandin E2 levels in rat gastric mucosa. In untreated controls, prostaglandin E2 levels were higher in the antral than the fundic mucosa. Stress experiments showed tht 30-min stress induced no gastric lesions but effected a significant (p less than 0.05) increase in antral prostaglandin E2: after 7-hr stress exposure, hemorrhagic lesions and prostaglandin E2 levels significantly (p less than 0.05) below normal control values were noted. The formation of HCl-induced gastric mucosal lesions was markedly inhibited if 30-min stress preceded HCl-administration. The infusion of 5 microgram/kg 16, 16-dimethyl prostaglandin E2 prior to 7-hr stress exposure inhibited ulcer formation markedly. Our results suggested that stress-induced decrease in intramucosal prostaglandin E2 plays an important role in the pathogenesis of stress ulcer formation.