肢体缺血后处理对脑缺血-再灌注过氧化损伤的影响

摘要

目的:探讨肢体缺血后处理(LPostC)对脑缺血-再灌注(I/R)过氧化损伤的作用及其机制.方法:32只雄性昆明小鼠随机均分为假手术组(Sham组)、脑I/R模型组(I/R组)、I/R+后处理(PostC)组(PostC组)和I/R +LPostC组;除Sham组外,其余各组均缺血1.5 h,术后24 h处死实验小鼠.小鼠运动行为变化按Longa标准进行评分;检测脑组织中丙二醛(MDA)含量和超氧化物歧化酶( SOD)活性.结果:与I/R组比较,I/R+LPostC和I/R+ PostC组脑再灌注损伤程度呈现不同程度减轻,行为学评分降低(P<0.01).与Sham组比较,I/R组MDA水平明显升高,SOD 活性明显降低(P<0.01);与I/R组比较,I/R+PostC和I/R+LPostC组MDA 含量明显降低(P<0.05),SOD 活性明显升高(P<0.05).结论:LPostC抑制小鼠脑I/R过氧化损伤,改善神经行为;其机制可能与LPostC能够减少脑组织活性氧生成和促进其清除有关.%Objective:To investigate the effect of transient limb ischemic posteonditioning (LPostC) on mouse against focal cerebral ischemia-reperfusion(I/R) injury. Methods: Thirty two male mice were randomly divided into four groups, 8 in each group: Sham group,I/R group,I/R + PostC group and I/R + LPostC groups. Twenty-four hours after the reperfusion, the neurologic deficit scores were recorded according to Longa standard and the brains were obtained to measure superoxide dismutase (SOD) activity and malondialdehyde(MDA) content. Results: Compared with I/R group, the neurologic deficit scores of I/R + LPostC group and I/R + PostC group were significantly decreased ( P ＜ 0.01 ). Compared with Sham group, the content of cerebral tissue MDA was markedly increased,and the activity of SOD was decreased significantly in I/R group. Compared with I/R group,in I/R + LPostC group and I/R + PostC group, the activities of SOD in the cerebral tissues were enhanced ( P ＜ 0.05 ), and the contents of MDA in the cerebral tissues were decreased(P ＜ 0.05). Conclusions: LPostC can attenuate focal cerebral ischemic reperfusion induced brain injury, improve neurological behavior and increase the ability of resisting brain injury. The protective mechanism of LPostC may be related to reduce reactive oxygen species production and promote its clearance in brain injury.