电针对脑缺血再灌注后大鼠脑缺血区生长相关蛋白-43与神经蛋白聚糖表达的影响

摘要

目的 探讨电针治疗对脑缺血再灌注后大鼠脑缺血区不同时间点生长相关蛋白(GAP)-43及神经蛋白聚糖(Neurocan)表达的影响.方法 将60只健康成年SD雄性大鼠随机分为假手术组(n=10)、大脑中动脉闭塞再灌注(MCAOR)组(n=25)和治疗组(n=25).用线栓法建立右侧MCAOR模型,治疗组选取人中、百会穴给予电针刺激.选取1、3、7、14、21 d五个时间点,应用免疫组化、RT-PCR方法检测缺血区皮层GAP-43及Neurocan阳性细胞及其mRNA的表达情况.结果 GAP-43及Neurocan在假手术组不表达,MCAOR后表达增加,且电针治疗组较MCAOR组表达差异显著(P<0.01).缺血2 h再灌注1 d MCAOR组出现GAP-43及Neurocan阳性表达细胞,并且呈先递增后减少的趋势.再灌注后7 d时,MCAOR组的GAP-43阳性细胞及其mRNA表达达到高峰,14 d时降至接近初始水平,但治疗组GAP-43表达仍维持较高水平.MCAOR组的Neurocan阳性细胞及其mRNA 7 d明显增多,14 d达高峰,21 d时下降,但仍高于假手术组水平(P<0.01);治疗组 Neurocan表达在缺血再灌注3、7、14、21 d较对照组显著减少(P<0.01).结论 电针上调脑缺血区GAP-43表达与下调Neurocan表达,可能是其促进脑损伤区中枢神经修复的重要机制之一.%Objective To investigate the effect of electroacupuncture (EA) on GAP43 and neurocan expression in the ischemic cortex in rats after middle cerebral artery occlusion and reperfusion (MCAOR).Methods 60 healthy adult male SD rats were randomly divided into sham-operated (n = 10) ,MCAOR (n =25) and treatment groups ( n =25 ).MCAOR model in the right was made by nylon monofilament.The rats in the EA group received EA treatment at Renzhong and Baihui acupoints after MCAOR.The rats were randomly divided into different time points (24 h, 3,7,14,21 d after repeffusion).Immunohistochemistry and RT-PCR were used to detect the expressions of GAP-43 and neurocan in the ischemic cortex.Results No positive GAP43 and neurocan cells were detected in sham-operated group.And the expressions of GAP-43 and neurocan after MCAOR were obviously increased in treatment group compared with those of MCAOR group (P ＜0.01 ).After 2 hour ischemia and 1 day reperfusion, positive GAP-43 and neurocan cells were detected in the MCAOR group, and their expression were increased firstly and then decreased.GAP-43 positive cells and mRNA in MCAOR group reached the peak level in 7 d after MCAOR, and dropped to incipient level in the 14 d.While the expression of GAP-43 in treatment group retained higher than that of MCAOR group.The expression of positive neurocan cells and mRNA in MCAOR group were increased significantly after 7 d and reached the maximum in 14 d after reperfusion, and then it was decreased after 21 d but still higher than that of sham-operated group ( P ＜0.01 ).Compared with the MCAOR group, the expression of neurocan in treatment group was decreased in 3,7,14 and 21 d after repeffusion (P＜0.01 ).Conclusions EA may upregulate the expression of GAP-43 and downregulate the expression of neurocan, which is one of the vital mechanism for the nerve repair of CNS after brain damage.