电针不同穴组对心肌缺血大鼠海马脑源性神经营养因子、酪氨酸激酶B表达的影响

目的:观察电针心经原穴及其配穴对心肌缺血大鼠大脑的保护作用以及脑源性神经营养因子(BDNF)、酪氨酸激酶B(TrkB)表达的影响,探讨电针抗心肌缺血脑损伤的作用机制。方法:80只SD大鼠随机选取15只作为伪手术组,其余大鼠采用冠状动脉左前降支结扎方法复制心肌缺血大鼠模型。模型复制成功大鼠随机分为模型组、神门组、神门+心俞组和神门+支正组,每组15只。神门组电针"神门"穴,神门+心俞组电针"神门""心俞",神门+支正组电针"神门""支正",每日治疗1次,共治疗1周。采用免疫组织化学法和实时荧光定量PCR方法检测各组大鼠海马组织BDNF、TrkB蛋白及mRNA的表达。结果:各组均可见BDNF、TrkB阳性细胞表达,各电针组海马BDNF、TrkB免疫反应阳性神经元数目较模型组明显增加(P0.01);与模型组比较,各电针组大鼠海马BDNF mRNA和TrkB mRNA表达量升高(P0.05,P0.01);神门+心俞组和神门+支正组海马BDNF、TrkB免疫反应阳性神经元数和BDNF mRNA、TrkB mRNA表达高于神门组(P0.01,P0.05)。结论:电针不同配穴对心肌缺血大鼠的脑保护作用有协同效应,神门+心俞组与神门+支正组的调整效应优于神门组,电针上调心肌缺血大鼠海马BDNF、TrkB表达可能是其抗心肌缺血脑损伤的作用机制之一。

Electroacupuncture Stimulation of Different Acupoint or Paired Acupoints on Expression of BDNF and TrkB Proteins and Genes in Hippocampus in Myocardial Ischemic Rats

Objective To observe the protective effect of electroacupuncture(EA)intervention on the expression of brain-derived neurotrophic factor(BDNF)and tropomyosin receptor kinase B(TrkB)proteins and genes in the hippocampus areas in myocardial ischemia(MI)rats,so as to reveal its underlying mechanisms in protecting hippocampal cells under MI.Methods Eighty healthy male SD rats were randomized into sham-operation(sham),MI model,Shenmen(HT 7),HT 7-Zhizheng(SI 7)and HT 7-Xinshu(BL 15)groups(n=15in each group).The MI model was established by occlusion of the anterior descending branch of the left coronary artery.EA(2Hz,2mA)was applied to bilateral HT 7,HT 7-SI 7,and HT 7-BL 15,respectively for15 min,once per day for a week.The number of BDNF and its receptor TrkB positive cells in the left hippocampus and that of mRNAs in the right hippocampus tissue were determined by immunohistochemistry and real-time fluorescence quantitative PCR,respectively.Results In comparison with the sham group,the numbers of both BDNF and TrkB positive cells in the left hippocampus and the expression levels of BDNF mRNA and TrkB mRNA in the right hippocampus were increased slightly(P>0.05).After EA intervention,the numbers of hippocampal BDNF and TrkB positive cells and the expression levels of BDNF mRNA and TrkB mRNA were evidently up-regulated(P<0.05,P<0.01),and the effects of HT 7-SI 7and HT 7-BL 15 were obviously superior to those of simple HT 7in up-regulating BDNF and TrkB expression(P<0.01,P<0.05).No significant differences were found between the HT 7-SI 7and HT 7-BL 15 groups in increasing the number of hippocampal BDNF and TrkB positive cells and in up-regulating expression of both BDNF mRNA and TrkB mRNA(P>0.05).Conclusion EA intervention is effective in increasing the expression of hippocampal BDNF and TrkB in MI rats,which may contribute to its effect in protecting hippocampal cells from injury under MI condition.The effect of EA stimulation of HT 7-SI 7and HT 7-BL 15 was obviously superior to that of simple HT 7in up-regulating BDNF and TrkB expression.