电针对脑缺血再灌注损伤大鼠脑组织中自由基及热休克蛋白70表达的影响

目的:探讨电针干预脑缺血再灌注损伤的作用机制。方法:成年Wistar大鼠63只,分为7组,脑缺血2h/再灌注1h组、脑缺血2h/再灌注1h+电针组、脑缺血2h/再灌注3h组、脑缺血2h/再灌注3h+电针组、脑缺血2h/再灌注6h组、脑缺血2h/再灌注6h+电针组和假手术组。建立局灶性脑缺血再灌注动物模型。电针取“水沟”、双侧“中冲”及“风府”穴,疏密波,4-60Hz,强度2mA左右,在大脑中动脉阻断1h后给予电刺激15min。分别用羟胺法和硫巴比妥酸盐反应法检测脑组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,免疫组化法测定脑组织中热休克蛋白(HSP)70的表达。结果:与假手术组相比,各缺血再灌注组SOD活性明显下降,MDA含量显著增加,HSP70表达增加。与缺血再灌注组比较,各电针组SOD活性明显上升,MDA含量明显下降,HSP70表达进一步增加。结论:电针干预脑缺血再灌注损伤的作用机制与降低大鼠脑组织中自由基含量,增强SOD活性和HSP70表达有关。

Effect of Electroacupuncture on Free Radical Content and HSP70 Expression in the Brain Tissue in Rats with Cerebral Ischemia-reperfusion Injury

OBJECTIVE: To study the mechanism of electroacupuncture (EA) in treating ischemic cerebrovascular disease. METHODS: Reversible cerebral ischemia/reperfusion (CI/R) model of rats was established by occlusion of the middle cerebral artery and reperfusion. Sixty-three Wistar rats were randomized into sham-operation, CI-2 h/R-1 h, CI-2 h/R-1 h+ EA, CI-2 h/R-3 h, CL-2 h/R-3 h+EA, CI-2 h/R-6 h, CI-2 h/R-6 h+ EA groups with 9 cases being in each group. EA (4/60 Hz in frequency, 2 mA) was applied to "Shuigou" (GV 26), "Zhongchong" (PC 9) and "Fengfu"(GV 16) for 15 min. After decapitation, the rats' brain tissue was collected for detecting superoxide dismutase (SOD) activity and malondialdehyde (MDA) content by using nitroblue tetrazolium hydroxylamine method and thiobarbituric barbiturate reaction method separately. HSP70 expression was measured by immunohistochemical technique. RESULTS: Compared with sham-operation group, SOD activity in CI-2 h/R-1 h, CI-2 h/R-3 h and CI-2 h/R-6 h groups decreased obviously (P < 0.01), and MDA contents in these 3 CI/R groups increased obviously (P < 0.01), while compared with their corresponding CI/R groups, SOD activity increased considerably and MDA contents lowered apparently in the CL-2 h/R-1 h+ EA, CI-2 h/R-3 h+ EA and CI-2 h/R-6 h+ EA groups (P < 0.05, 0.01). HSP70 expression presented a marked increase tendency in the 3 CI/R groups and after EA the expression increased further. CONCLUSION: EA can raise SOD activity, lower MDA content in the brain tissue and enhance HSP70 expression in CI/R rats.