不同频率电针“内关”穴对心肌缺血再灌注大鼠血管活性物质的影响

Effects of Electroacupuncture Stimulation of“Neiguan”(PC 6)at Different Frequencies on Plasma Vasoactive Substance Levels in Myocardial Ischemic Reperfusion Rats

目的:比较不同频率电针"内关"穴对心肌缺血再灌注大鼠血液中血管活性物质含量的影响,并分析不同频率电针改善心肌缺血再灌注损伤的作用机制。方法:40只Wistar大鼠随机分为假手术组、模型组、高频电针组及低频电针组。除假手术组外,其余各组结扎左冠状动脉前降支30min并再灌注40min造成心肌缺血再灌注模型,高频电针组及低频电针组于结扎成功即刻起分别以120Hz及20Hz持续电针"内关"穴50min。采用放射免疫法检测各组血浆内皮素(ET)、心钠素(ANP)、血栓素B 2(TXB2)、6-酮-前列腺素F1α(6-Keto-PGF1α)含量,并采用硝酸还原酶法检测各组血清一氧化氮(NO)水平。结果:模型组与假手术组比较,血浆ET、ANP、TXB2含量显著升高(P<0.05),血浆6-Keto-PGF1α含量显著下降(P<0.05),血清NO含量有所下降,但差异无统计学意义(P>0.05)。与模型组相比,高频电针组和低频电针组的血浆ET、ANP、TXB2含量均有显著降低,血浆6-Keto-PGF1α含量及血清NO含量显著升高(P<0.05)。高频电针组血清NO含量显著高于低频电针组(P<0.05)。结论:电针大鼠"内关"穴可以调节血管活性物质,这可能参与了对心肌缺血再灌注的治疗作用。此外,不同频率电针对血管活性物质的调节作用不完全相同,这可能是不同手法针刺疗效存在差异的原因之一。

Objective To observe the effect of electroacupuncture（EA）stimulation of＂Neiguan＂（PC 6）at different frequencies on plasma vasoactive substance levels in myocardial ischemia-reperfusion（MIR）injury rats,so as to explore its mechanisms underlying improvement of acute myocardial ischemia.Methods A total of 40 Wistar rats were randomized into control,model,high frequency（HF,120Hz）and low frequency（LF,20Hz）groups（n=10in each group）.The MIR model was established by occlusion of the anterior descending branch（ADB）of the left coronary artery for 30 min,followed by reperfusion for40 min.EA（3V,120 Hz or 20Hz）was applied to bilateral＂Neiguan＂（PC 6）for 50 min immediately after occlusion of ADB.Subsequently,the contents of plasma endothelin（ET）,atrial natriuretic peptide（ANP）,thromboxane B 2（TXB2）and 6-Keto-PGF1αwere assayed by radioimmunoassay,and the content of serum nitric oxide（NO）was detected by nitrate reductase method.Results Compared with the control group,the contents of plasma ET,ANP and TXB2 in the model group were significantly increased（P〈0.05）,and that of plasma 6-Keto-PGF1αin the model group was notably decreased（P〈0.05）,but no significant change was found in serum NO level（P〉0.05）.Compared with the model group,the contents of plasma ET,ANP and TXB2 were considerably decreased,and plasma 6-Keto-PGF1α and serum NO contents were obviously increased in both HF and LF groups（P〈0.05）.No significant differences were found between the HF and LF groups in plasma ET,ANP,TXB2 and 6-KetoPGF1αcontents（P〉0.05）,but the HF EA was markedly superior to the LF EA in up-regulating the content of serum NO（P〈0.05）.Conclusion EA stimulation of＂Neiguan＂（PC 6）can down-regulate the contents of plasma ET,ANP and TXB2 and up-regulate contents of plasma 6-Keto-PGF1αand serum NO in MIR rats,which may contribute to its effect in relieving acute ischemic myocardial injury.The effect of HF EA is better than LF EA in raising blood NO level.