运动预处理对局灶性缺血再灌注大鼠脑梗死和HIF-1α基因表达的影响

Reduction of Focal Cerebral Reperfusion-induced Cerebral Infarction Volume by Exercise Preconditioning

目的:探讨运动预处理对局灶性脑缺血再灌注诱导的大鼠脑梗死的影响及其可能机制。方法:将60只雄性SD大鼠随机分为缺血再灌注组(IR组,n=24)、假手术组(sham组,n=12)和运动预处理组(EP组,n=24),EP组进行持续4周的中等负荷游泳训练后,IR组和EP组采用线拴法制作大鼠局灶性脑缺血再灌注模型。Sham组行假手术代替缺血再灌注。采用2%TTC(氯化三苯基四氮唑)溶液对各组大鼠脑组织染色,计算脑梗死体积及梗死百分比。采用荧光定量RT-PCR、免疫组织化学及Western blot检测低氧诱导因子-1α(HIF-1α)基因及其蛋白表达。结果:sham组未见脑梗死现象及明显HIF-1α表达,EP组大鼠脑HIF-1α基因转录和蛋白翻译水平显著高于IR组(P<0.05),梗死面积较IR组减少37.01%(P<0.05)。结论:运动预处理能减少局灶性缺血引起的大鼠脑梗死体积,可能通过上调HIF-1α表达产生保护作用。

Objective To study the effect and mechanism of exercise preconditioning on the cerebral infarction induced by focal cerebral ischemia reperfusion in rat. Methods Sixty SD rats were divided into three groups at random： ischemia reperfusion group （IR, n = 24）, sham group （sham, n = 12） and exercise preconditioning group（EP,n = 24）. Rats in group EP carried out exercise preconditioning（swimming 60 min/d,6 days/wk）for 4 weeks. Then cerebral ischemia reperfusion injury of rats in group EP and IR was established using Zea Longa＇s thread method. The cerebral infarction volume of rat in different groups was evaluated by 2% TYC staining,expression of HIF-1α in rat brain was detected by real-time RT- PCR,immunohistochemistry method and Western blot. Results No cerebral infarction and significant expression of HIF-1α in group sham were observed. When compared with group IR,there was smaller infarction volume and stronger HIF-1α expression（both in mRNA and protein）in group EP（P 〈 0.05）. Conclusion Moderate exercise preconditioning reduces the volume of ischemia reperfusion-induced focal cerebral infarction through up-regulating the expression of HIF-1α.