电针不同经穴对心肌缺血模型大鼠大脑皮质区神经生长因子、酪氨酸激酶A表达的影响

Effect of Electroacupuncture at Different Acupoints on Expression of NGF and TrkA in Cerebral Cortex in Rats with Myocardial Ischemia

目的:观察电针心经原穴"神门"、小肠经络穴"支正"和背俞穴"心俞"对心肌缺血大鼠大脑皮质内神经生长因子(NGF)及其受体酪氨酸激酶A(TrkA)表达的影响,比较针刺不同经穴抗心肌缺血效应的差异,探讨针刺经穴效应的相对特异性。方法:雄性SD大鼠随机选取10只为假手术对照组,其余70只采用左冠状动脉前降支结扎法复制急性心肌缺血模型,模型复制成功的大鼠采用随机数字表分为模型组、神门组、支正组和心俞组,每组15只。各电针组电针相应穴位,每天治疗1次,每次15min,共治疗7d。采用免疫组化法和实时荧光定量PCR技术检测各组大鼠大脑皮质中NGF及其受体TrkA的表达。结果:与假手术组比较,模型组大鼠大脑皮质NGF及其受体TrkA阳性细胞数以及NGF、TrkA mRNA的表达差异无统计学意义(P>0.05)。与模型组比较,各针刺治疗组的大脑皮质NGF及其受体TrkA阳性表达细胞数目和NGF、TrkA mRNA表达均有显著增加(P<0.01,P<0.05)。与支正组及神门组比较,心俞组大脑皮质NGF、TrkA阳性细胞数和NGF、TrkA mRNA表达增多(P<0.01,P<0.05)。结论:电针"神门""支正""心俞"均能够提高心肌缺血大鼠大脑皮质中NGF及其受体TrkA的表达水平,且"心俞"穴效应最佳,具有相对特异性。

Objective To compare the therapeutic effect of electroacupuncture（EA）of＂Shenmen＂（HT 7,Yuan point of the Heart Meridian）,＂Zhizheng＂（SI 7,Luo point of the Small Intestine Meridian）and＂Xinshu＂（BL15,Back-shu point）on the expression of nerve growth factor（NGF）and its receptor,tyrosine kinase A（TrkA）in the cerebral cortex of myocardial ischemia（MI）rats.Methods A total of 70 male SD rats were randomized into sham operation（sham,n=10）,model,HT 7,SI 7,and BL15 groups（n=15 in each of the latter 4 groups）.The MI model was established by ligation of the anterior descending branch of the left coronary artery.EA（1 mA,2 Hz）was respectively applied to HT 7,SI 7 and BL15 for 15 min,once per day for 1 week.Immunohistochemistry and real-time fluorescent quantitative PCR were used to detect the expression of NGF and TrkA proteins and genes in the cerebral cortex.Results Compared with the sham group,no significant changes were found in the number of NGF immune-reaction（IR）-positive and TrkA IR-positive cells,and the expression levels of NGF mRNA and TrkA mRNA in the model group（P〈0.05）.After EA intervention,the number of NGF and TrkA IR-positive cells and the expression of NGF mRNA and TrkA mRNA in each of the 3 EA groups were significantly increased relevant to the model group（P〈0.01,P〈0.05）.The effect of EA at BL 15 was significantly superior to that of EA at HT 7 and SI 7 in increasing the number of NGF and TrkA positive cells and up-regulating the expression of their mRNAs（P〈0.01,P〈0.05）.Conclusion EA at HT 7,SI 7 and BL 15 can increase the levels of expression of NGF and TrkA proteins and mRNAs in the cerebral cortex of subacute MI rats and the effects of EA-BL 15 are obviously superior to those of EA-HT 7 and EA-SI 7,suggesting a relative specificity of the effect of EA at different acupoints.