Effect of Naloxone on Hippocampal Neurons and Metabolism of Oxygen-derived Free Radidicals in Rat Cerebral Ischemia Reperfusion Injury

Objective To explore the preventive effect of Naloxone on Cerebral Ischemia Reperfusion Injury and its mechanism in rat.Methods The rats were randomized into the sham operation group,ischemia-reperfusion injury group(I/R),Naloxone-treated group and dan-shen root treated group.All rats except for those in the sham operation group were subjected to transient global ischemia using four-vessel occlusion.The reperfusion was started at 30min after 10min ischemia,then the concentration of malondialdehyde(MDA),the activity of superoxide dismutase(SOD) and the water content of the rat brain tissue were detected,then the count and the pathological change of neurons in hippocampal CA1 were studied.Results The concentration of MDA and water content of the brain tissues increased remarkably and the superoxide dismutase(SOD) reduced significantly;the count of normal neurons in Hippocampi CA1 decreased significantly and neuron injured noticeably in ischemia-reperfusion injury group(P0.05 and P0.01).In Naloxone-treating group,the indexes of abnormal changes mentioned above were improved markedly,and there was significant difference between I/R group and Naloxone group(P 0.05 and P0.01).Conclusion Naloxone could improve the brain ischemia-reperfusion injury,its mechanism may relate to the decreased oxygen free radicals level.