FREE-RADICAL SCAVENGERS PREVENT REFLUX ESOPHAGITIS IN RATS

Free radical damage in reflux esophagitis of rats induced by 24-hr duo denojejunal ligation was studied. Oxygen free radicals were selectivel y blocked. Groups were: sham operation, reflux, reflux + superoxide di smutase (SOD), catalase, dimethylthiourea, allopurinol, and inactivate d SOD or inactivated catalase alone or in the combination SOD + catala se or SOD + catalase + dimethylthiourea + allopurinol. Macroscopic eso phagitis was inhibited only by SOD, alone or in combination with other agents. Esophageal mucosal lipid peroxidation was 10-fold increased i n the reflux group compared to the sham group (P < 0.05). This respons e was damped by SOD > catalase (P < 0.05) but not by the inactivated e nzymes, dimethylthiourea or allopurinol. SOD + catalase showed no sign ificant improvement on SOD alone. Total inhibition of lipid peroxidati on was achieved by combining all scavengers. Total glutathione (GSH) i n the esophageal mucosa was stimulated by reflux. This response was in hibited by scavengers equivalent to their efficacy in preventing lipid peroxidation. It is concluded that reflux esophagitis is associated w ith free radical release with O-2(-) being the main source. Free radic als appear to stimulate GSH production in this prolonged oxidative str ess.