PROTECTION BY ANTOXIDANTS OF ISCHEMIC CELLULAR DAMAGE

点击翻译按钮获取中文摘要

Liver ischemia-reperfusion induced cellular damage caused by stimulated lipid peroxidation on biomembranes, especialy after reperfusion, which resulted in a marked decrease in ATP resynthesis after reperfusion due to mitochondrial dysfunction, and a decrease in the survival rate depending on ischemic periods. The administration of either coenzyme q_<10> (CoQ_<10>) or <alpha>-tocopherol (<alpha>-Toc) prior to ischemia completely suppressed the stimulated lipid peroxidation, and raised ATP resynthesis due to reversal of the mitochondrial dysfunction, which were accompained by a marked rise in the survival rate from 0% to 60% after 90-min ischemia. When endogenous levels of CoQ_<10> homologs (CoQ_9, CoQ_<10>), <alpha>-Toc and reduced glutathione (GSH) in the liver were determined during 90-min ischemia and following 60-min reperfusion period, the lwvels of <alpha>-Toc and GSH decreased during ischemia, which were not protected by CoQ_<10> pretreatment. The levels of endogenous antioxidant … More s tested decreased markedly after reperfution following to ischemia, which were completely reversed by the administration of either CoQ_<10> or <alpha>-Toc. These results obtained are compatible with the assumption that cellular damage caused by hepatic ischemia-reperfusion can be explained by free radical injury, and that antioxidants administered can protect cellular damage from lipid peroxidation by either radical scavenging and antioxidant actions.The protective effect of CoQ_<10> on ischemic damage could be demonstrated with orthotopic transplantation of the rat liver subjected to warm ischemia for 30 min: the survival rate of recipient rats increased from 0% to 45% in CoQ_<10>-pretreated group.Cellular damage due to endotoxemia was also explained, at least in part, by stimulated lipid peroidation. The administration of CoQ_<10> and <alpha>-Toc completely suppressed lipid peroxidation with a marked improvement of energy metabolism as well as endogenous levels of antioxidants, which, resulted in a marked rise of the survival rate. Less