Superoxide: a critical oxygen-free radical in ischemic bowel injury.

The radical anions of molecular oxygen reduction, superoxide (O2), hydrogen peroxide (H2O2), and hydroxyl radical (OH), have been implicated in a number of disease processes, including ischemic bowel injury. This report evaluates the effect of superoxide dismutase (SOD), catalase (CAT), dimethyl sulfoxide (DMSO), selenium treatment, and selenium deficiency on bowel integrity and survival in experimental intestinal ischemia in rats. Ischemic bowel injury was produced in 204 male Sprague-Dawley rats (wt 90 to 100 g) by a one-minute occlusion of the superior mesenteric artery (SMA) with a microaneurysm clip. Experiment I treatment animals (n = 20) received 2.5 mg/kg SOD dissolved in Ringer's lactate, and control animals (n = 71) received Ringer's lactate alone. Experiment II treatment animals (n = 16) received 1 cc of 100% DMSO gavage, and control animals (n = 11) received no treatment. Experiment III treatment animals (n = 17) received 25 mg/kg CAT dissolved in phosphate buffered saline, and control animals (n = 11) received nothing. Experiment IV treatment animals (n = 14) received 300 micrograms of sodium selenate by gavage dissolved in deionized water, and control animals (n = 15) receiving nothing. Experiment V treatment animals (n = 20) were raised from 35 to 50 g size on a selenium deficient diet, and control animals were raised (n = 20) on a normal rat chow diet, until they weighed 100 g when ischemia was induced. At seven days, survival, incidence of bowel perforation or necrosis, and length of survival were compared in each experiment between control and treatment groups using chi 2 analysis.(ABSTRACT TRUNCATED AT 250 WORDS)