重复电针预处理对脑缺血再灌注大鼠脑皮层热休克蛋白70表达的影响

Effects of pretreatment with repeated electroacupuncture on heat shock protein 70 expression after cerebral ischemia-reperfusion Injury In rats

目的 探讨重复电针刺激百会穴预处理对脑缺血再灌注大鼠脑皮质热休克蛋白70表达的影响。方法 20只雄性SD大鼠,随机分为对照组(n=10)和电针组(n=10)。对照组未行任何预处理;电针组予电针刺激百会穴,30 min·d-1,连续5d。最后一次预处理后24 h时,两组均采用颈内动脉尼龙线线栓法致大脑中动脉阻闭(120 min)。缺血再灌注后24 h将大鼠灌注固定,取脑组织行病理学观察及免疫组织化学染色,并按照McCarthy等的方法对免疫组化染色结果进行半定量分析。结果 半定量分析结果,电针组皮层HSP70表达(1.9±0.6)明显强于对照组(0.9±0.4)(P<0.05)。电针组组织病理学损害轻于对照组。结论 重复电针刺激百会穴预处理减轻脑缺血再灌注损伤与皮层HSP70表达增强有关。

Objective To investigate if pretreatment with repeated electroacupuncture (EA) at Baihui acupoint could increase HSP 70 expression after cerebral ischemia-reperfusion injury in rats.Methods Twenty male SD rats weighing 280-320 g were randomly divided into 2 equal groups of ten : control group received no pretreatment and EA group received pretreatment with EA at Baihui acupoint 30 min a day for 5 days. The animals in both groups were anesthetized with isoflurane. Right common carotid artery (CCA) , external and internal carotid artery (EGA, 1C A) were exposed through a longitudinal incision in the neck. EGA was ligated and a 3-0 nylon monofilament (Ethicon) with rounded tip was inserted into ICA and threaded cephalad until resistance was felt. In this way middle-cerebral artery was occluded for 120 min in both groups. The nylon filament was then withdrawn to allow reperfusion. The animals were allowed to recover. At the end of 24 h reperfusion, the animals were anesthetized with intraperitoneal pentobarbital 40 mg·kg-1 and killed. Brain was immediately removed. Two pieces of brain tissue were obtained from right parietal lobe for microscopic examination (HE staining) and determination of expression of heat shock protein (HSP) 70 using immuno-histochemistry technique.Results In EA group the levels of HSP 70 expression were significantly increased (1.94±0.57) compared with those in control group (0.86±0.35) ( P < 0.05 ) . Microscopic examination showed that there were less neurons with swelling, pink-stained cytoplasm and irregular condensed nuclei in EA group as compared with control group. Conclusion Pretreatment with repeated EA at Baihui acupoint can increase levels of HSP 70 expression after transient middle cerebral artery occlusion, thus increase the resistance of the brain to ischemia-reperfusion injury.