脑缺血再灌注致小鼠神经元退行性变进程中自由基水平和SOD-1表达的变化

目的探讨脑缺血再灌注(ischemia/reperfusion,I/R)致神经元退行性变自由基和SOD-1表达的时程变化。方法 NIH小鼠160只,分为I/R组和假手术组,每组80只。抽取并回输约40%总血量加双侧颈总动脉夹闭20 min建立I/R损伤模型。分别于术后5、15、30、60 d以光学显微镜观察神经元损伤;Morris水迷宫评价学习记忆能力;分光光度计法检测SOD-1活性和丙二醛(MDA)含量;RT-PCR和Western blot分别检测海马SOD-1 mRNA和蛋白表达。结果假手术组脑组织MDA含量、SOD-1活性及蛋白、mRNA表达分别为(0.549±0.049)nmol/mg、(55.134±4.076)U/mg、30.413±2.962和104.541±18.825。与假手术组比较,I/R组小鼠学习记忆能力显著降低,术后5、15、30、60 d脑组织MDA含量(0.673±0.087)、(0.782±0.101)、(0.719±0.094)、(1.084±0.140)nmol/mg]进行性显著升高(P<0.05);术后5 d和15 d I/R组SOD-1活性(42.522±3.701)、(37.011±4.843)U/mg]和蛋白表达(23.145±3.476、15.746±2.344)显著降低(P<0.05);术后30 d和60 d I/R组SOD-1活性(51.801±6.706)、(50.202±6.488)U/mg]与假手术组间差异无显著性(P>0.05),但SOD-1蛋白表达(40.587±6.154、44.263±6.597)较假手术组显著升高(P<0.05);各组SOD-1 mRNA表达水平无显著差异(P>0.05);组织学检测显示I/R组海马出现进行性神经元核固缩加重和神经元丢失。结论 I/R致小鼠神经元退行性变与SOD-1表达和功能异常和氧化应激进行性增强有关。

Level of free radicals and expression of SOD-1 in neuronal degeneration mice due to cerebral ischemia-reperfusion

Objective To study the changes of three radicals and expression of SOD-1 in neuronal degeneration due to cerebral ischemia/reperfusion(I/R) in mice.Methods One hundred and sixty NIH mice were divided into I/R group and sham operation group,80 mice in each group.A cerebral I/R model was established by drawing out and reperfusing 40% of the whole blood volume and clamping the bilateral carotid arteries for 20 min.On days 5,15,30,and 60 after cerebral I/R,neuronal injury was observed under a light microscope,l...