针刺太阳、风池穴对脑缺血再灌注家兔热休克蛋白70及细胞凋亡的影响

Effect of Acupuncture at Points Taiyang and Fengchi on Heat Shock Protein 70 and Apoptosis during Cerebral Ischemia and Reperfusion in Rabbits

目的观察针刺太阳、风池穴对家兔局灶脑缺血再灌注损伤后热休克蛋白70(HSP70)表达和神经细胞凋亡的影响,并探讨其对神经细胞保护作用及机制。方法将家兔随机分为假手术组、模型组和针刺组,每组又随机分为1 d、3 d和7 d 3个时间点。采用大脑中动脉线栓法(MCAO)建立家兔局灶性脑缺血再灌注模型,在脑缺血2 h后进行再灌注。针刺组家兔在脑缺血6 h后采用电针太阳、风池穴进行治疗,每日1次。在再灌注后1、3、7 d分别处死取材。HE染色观察脑组织病理改变,免疫组化法检测脑组织HSP70蛋白表达,原位末端标记(TUNEL)法检测神经细胞凋亡。结果病理染色显示与模型组相比,针刺组各时间点家兔脑组织梗死面积明显减小,神经细胞数目增多,炎性浸润程度减轻。组化结果显示HSP70蛋白在假手术组表达较低,模型组呈现出高表达。与模型组相比,针刺组各相应时间点均明显著增多(P<0.01)。模型组的凋亡细胞数随再灌注时间的延长而逐渐增多,在3 d时达高峰;针刺组各时间点凋亡细胞数均明显减少,与模型组比较,差异均具有统计学意义(P<0.01)。结论电针太阳、风池穴能够增加脑中HSP70蛋白的表达和减少神经细胞凋亡,从而对脑缺血再灌注损伤家兔起到神经保护作用。

Objective To investigate the effect of acupuncture at points Taiyang and Fengchi on the expression of heat shock protein 70 （HSP70） and neural cell apoptosis during local cerebral ischemia and reperfusion in rabbits and explore its protective action on nerve cells and the mechanism.Methods Rabbits were randomized into sham operation, model and acupuncture groups. Each group was randomly allocated to three time points： one, three and seven days. A rabbit model of local cerebral ischemia and reperfusion was made by middle cerebral artery occlusion （MCAO）using an intraluminal thread. Reperfusion was performed at two hours after cerebral ischemia. In the acupuncture groups, points Taiyang and Fengchi were electro-acupunctured at six hours after cerebral ischemia. Treatment was given once daily. The rabbits were sacrificed to take materials at one, three and seven days after reperfusion. Pathological changes in brain tissue were observed by HE staining. Cerebral HSP70 expression was determined by immunohistochemical method. Neural cell apoptosis was examined by TdT-mediated dUTP nick end labeling （TUNEL）.Results Pathological staining showed that cerebral infarction area decreased significantly, the number of nerve cells increased and inflammatory infiltration reduced at every time point in the acupuncture group of rabbits compared with the model group. The results of histochemical examination showed that HSP70 expression decreased in the sham operation group and increased in the model group. It increased significantly at every corresponding time point in the acupuncture group compared with the model group （P〈0.01）. The number of apoptotic cells increased gradually with reperfusion prolongation and reached the peak at three hours in the model group. The number of apoptotic cells decreased significantly at every time point in the acupuncture group and there was a statistically significant difference by comparison with the model group （P〈0.01）.Conclusions Electroacupuncture at points Taiyang and Fengchi can increase cerebral HSP70 expression and decrease neural cell apoptosis to produce a nerve-protecting effect in rabbits with cerebral ischemia-reperfusion injury.