AN INJURY OF THE LIVER CAUSED BY ISCHEMIA-REPERFUSION IN RAT-LIVER

Cellular damage of various organs by ischemia following reperfusion is assumed to be at least in part due to lipid peroxidation in biomembranes, and oxygen-derived free radicals play a major role. The level of lipid peroxides in liver tissue increased during 90-min ischemia. When reflow of hepatic blood was allowed, a greater increase in the lipid peroxides was observed. Similar increases were obtained in several serum markers (GOT, GPT and LDH) during the period of ischemia or ischemia-reperfusion. In addition, levels of cytochrome p-450 and NADPH cyt. c reductase activity decreased in proportion to the decrease in microsomal proteins during ischemia or ischemia-reperfusion. On the other hand, superoxide dismutase in blood was significantly increased by ischemia-reperfusion. Rats died within 2 days after liver ischemia of 90 min, while all animals subjected to 30-min ischemia survived. Histopathological examinations indicated that extensive coagulation with erythrocytes occurred and the extent was dependent on the time of ischemia. The liver injury by ischemia-reperfusion could be a useful experimental model for studying liver injury induced by free radicals, for developing hepatoprotective drugs, or for investigating liver transplantation.