Role of exogenous acid and retransfusion in hemorrhagic shock-induced gastric lesions in the rat.

The separate roles of exogenous acid, ischemia, and retransfusion of shed blood on gastric lesion formation in the rat hemorrhagic shock model were studied. In addition, the role of oxyradicals in lesion formation in this model was studied. Intragastric HCl increased gastric mucosal lesion formation in a dose-dependent manner. Even in the absence of intragastric HCl, ischemia followed by retransfusion of shed blood caused histologic mucosal injury in the corpus and antrum. Allopurinol, a xanthine oxidase inhibitor that prevents oxyradical formation, slightly, but significantly, reduced the gastric mucosal injury induced by ischemia-reperfusion but not that induced by ischemia alone. There was no significant difference in the extent of damage caused by ischemia-reperfusion and ischemia alone. We conclude that exogenous acid, ischemia, and oxyradical formation after retransfusion of shed blood are all important interacting factors in the rat hemorrhagic shock model of gastric mucosal injury. Allopurinol, by inhibiting formation of the oxyradical component, significantly protects against the injury.