Role of oxygen-derived free radicals in gastric mucosal lesions induced by burn injury in rats

This study examined the role of oxygen-derived free radicals in the pathogenesis of gastric mucosal lesions induced by burn injury in rats. Superoxide dismutase (SOD), catalase and combinations of SOD and catalase reduced ulcer index; in addition, SOD and catalase alone inhibited lipid peroxidation in the gastric mucosa. SOD combined with catalase inhibited the volume of gastric juice and acid output, but had no effects on the pH of gastric juice, total acidity, gastric blood flow or hexosamine contents in the gastric mucosa. Ulcer index was reduced in rats treated with allopurinol, but not in polymorphonuclear leukocytes-depleted rats. These results indicate that oxygen-derived free radicals from xanthine oxidase and lipid peroxidation play an important role in the pathogenesis of gastric mucosal lesions induced by burn injury in rats.