电针对缺血再灌注大鼠脑内小胶质细胞活化的影响

Effects of electroacupuncture on activation of microglia in the brain of ischemia-reperfusion rats

目的:观察局灶性脑缺血再灌注对大鼠脑内小胶质细胞活化的影响以及电针刺激水沟、百会(的调节作用。方法:实验于2002-03在华中科技大学同济医学院组织胚胎学教研室完成。取80只Wistar大鼠随机分为8组,每组10只:①正常对照组:不干预,次日处死。②假手术组:仅分离动脉,不插线栓,次日处死。③再灌注6,12,24h组:线栓法制备大鼠右侧大脑中动脉缺血再灌注模型,缺血30min后分别再灌注6,12,24h处死。④再灌注6h+电针组:同前造模,在栓线插入大脑中动脉造模成功后立即进行针刺(水沟、百会),加电刺激(疏密波,频率4Hz/16Hz,刺激强度从1V起,每10min增加1V,终强度为3V,每次持续刺激30min),缺血30min后再灌注6h处死。⑤再灌注12h+电针组:造模后立即针刺,隔8h后再针刺1次,参数同前。缺血30min后再灌注12h处死。再灌注24h+电针组:造模后立即针刺1次,每隔8h针刺1次,缺血30min后再灌注24h处死。切片组织采用免疫组织化学法以蓖麻凝集素标记小胶质细胞,计算小胶质细胞数量。结果:67只大鼠进入结果分析。正常对照组和假手术组未见显色,再灌注6,12,24h组在缺血灶边缘可见大量小胶质细胞活化,数量增加,再灌注12h达高峰,分别为(35.38±1.77),(54.25±1.67),(49.29±2.21)个/200倍视野;经电针治疗后,再灌注6,12,24h+电针组均低于同时段模型组[(32.11±2.80),(50.88±2.64),(45.45±3.95)个/200倍视野,P<0.05]。结论:脑缺血再灌注后脑内小胶质细胞被活化,对神经元产生毒性作用。电针治疗可减少小胶质细胞活化,从而对神经元发挥保护作用。

AIM：To study the effect of focal cerebral reperfusion on the activation of microglia and the regulation by acupoints on Shuigou （DU 26） and Baihui （DU 20） stimulated with electroacupuncture. METHODS： The experiment was conducted at Department of Histology and Embryology, Tongii Medical College, Huazhong University of Science and Technology during March 2002. Totally 80 Wistar rats were randomly divided into 8 groups with 10 in each group. ① Normal control group： The rats were not intervened, and killed at the following day. ② Sham operation group： Only artery separated, no suture inserted, and killed at the following day. ③ Reperfusion 6, 12 and 24 hours group： The ischemic reperfusion models of right middle cerebral artery （MCA） in rats were made by thread embolism method. After ischemia for 30 minutes, the rats were killed after reperfusion for 6, 12 and 24 hours, respectively. ④ Reperfusion for 6 hours ＋ electroacupuncture group： The models were made as before. After the success of building models in middle cerebral artery of thread, and the acupuncture （DU 20 and DU 26） was performed immedi- ately, with electrostimulating （D D mode, at the frequency of 4 Hz/16 Hz, the stimulus intensity from 1 V, adding 1 V every 10 minutes, the terminal intensity as 3 V, lasting for 30 minutes every time）, and after ischemia for 30 minutes and reperfusion for 6 hours the rats were killed. ⑤ Reperfusion for 12 hours ＋ electroacupuncture group： The acupuncture was performed in rats immediately after building the models. After 8 hours it was performed once, with the upper parameter. After ischemia for 30 minutes and reperfusion for 12 hours the rats were killed. Reperfusion for 24 hours ＋ electroacupuncture group： The acupuncture was performed in rats immediately after building the models. After 8 hours it was performed once. After ischemia for 30 minutes and reperfusion for 24 hours the rats were killed. RCA was used to identify the microglia with immunohistochemistry method in section tissue. The number of microglia was calculated. RESULTS： Sixty-seven rats were involved in the result analysis. No microglia was seen in the normal control group and sham operation group, large quantity of microglia was activated at the border of isehemic area in every model group, and their quantity largely increased, reaching apex at reperfusion for 12 hours （35.38±1.77）, （54.25±1.67）, （49.29±2.21）each/200-time visual field,respectively;The quantity in every electroacupuncture group was less than that in the corresponding model group [（32.11±2.80）, （50.88±2.64）, （45.45±3.95）each/200-time visual field ,P〈0.05]. CONCLUSION： The microglia in brain is activated after the cerebral ischemia-reperfusion to poison the neurons. The electroacupuncture can decrease the number of activated so as to protect the neurons.