电针诱导神经生长因子透血脑屏障效应及其机制分析

目的:观察电针"百会"哑门"诱导外源性神经生长因子(NGF)透过血脑屏障的效应及其促透效应与蛋白激酶C(PKC)信号传导通路的相关性。方法:采用急性反复脑缺血再灌注法制造脑缺血学习记忆障碍大鼠模型,3周后,将动物随机分为模型对照组、NGF组(尾静脉注射NGF)、电针组(电针"百会"哑门")、NGF+电针组(尾静脉注射NGF,同时"百会"哑门"通以电针)、NGF+H7+电针组(尾静脉注射NGF后注射异喹啉磺酰类H7,同时"百会"哑门"通以电针),另设假手术组,每组均8只大鼠。采用ELISA法检测各组大鼠脑组织中NGF含量。结果:NGF组大鼠脑组织中NGF含量与模型对照组比较,差异无统计学意义(P>0.05);NGF+电针组大鼠脑组织中NGF含量与假手术组、模型对照组、NGF组及电针组比较均明显升高,差异均有统计学意义(P<0.01);NGF+H7+电针组与NGF+电针组比较,脑组织中NGF含量有下降趋势,但差异不具统计学意义(P>0.05)。结论:"百会"哑门"电针能诱导NGF透过血脑屏障,使大鼠脑组织中NGF含量明显提高,该促透作用与PKC信号通路相关性不明显。

Effect of Electroacupuncture on the Permeability of Blood-Brain Barrier for Nerve Growth Factor and Its Relevance to PKC Pathway in Cerebral Ischemia Rats

Objective To observe the effect of electroacupuncture (EA) of "Baihui" (GV 20) and "Yamen" (GV 15) on the permeability of blood-brain barrier for exogenous nerve growth factor (NGF) and its relevance to PKC pathway in cerebral ischemia (CI) rats. Methods Forty-eight SD rats were randomized into sham-operation (sham), model, NGF, EA, NGF+EA, and NGF + H7 + EA groups. CI model was established by repeated occlusion of the bilateral carotid arteries and reperfusion. NGF (10 μg/kg) was administrated by intravenous injection (vena caudalis); while H 7 [1-(5-isoquinolinesulfonyl)-2-mehtylpopera-zine, an inhibitor of protein kinase C (PKC), 1 mg/kg] was given by intraperitoneal injection. EA (100 Hz, 2 mA) was applied to "Baihui" (GV 20) and "Yamen" (GV 15) for 20 min. NGF content in the brain tissue was assayed by enzyme-labeled immunosor-bent assay (ELISA). Results In comparison with sham group, cerebral NGF content had no apparent change in model group ( P>0. 05). Comparison among the abovementioned 6 groups showed that cerebral NGF level in NGF+ EA group was significantly higher than those in sham, model, EA and NGF groups (P<0. 01). No significant differences were found among sham, model, NGF, EA and NGF+ H7 + EA groups and between NGF + EA and NGF + H7 + EA groups in cerebral NGF contents ( P>0. 05). Conclusion EA of GV 20 and GV 15 can raise the permeability of blood-brain barrier for NGF to increase its level in the cerebral tissue in CI rats, favoring the regeneration and repair of nerves, which has no clear relevance to PKC pathway.