针刺对快速性心律失常大鼠心肌刺激性G蛋白mRNA表达影响的初步研究

Preliminary Study on the Effect of Electroacupuncture on Gs mRNA Expression in Tachyarrhythmia Rats

目的：探讨针刺“内关”穴对快速性心律失常的调节机制。方法：成年Wistar大鼠40只，随机分为正常组、乌头碱模型组、乌头碱加针刺穴位组、乌头碱加针刺非经非穴组。电针刺激乌头碱所致的心律失常模型大鼠双侧“内关”穴，疏密波，频率2～20Hz，强度2～3mA，针刺10min。观察针刺前后心律（率）变化；用半定量逆转录聚合酶链反应（RT-PCR）方法测定心肌中鸟苷酸结合蛋白（简称G蛋白）中刺激性G蛋白基因表达（Gs mRNA）的相对表达量。结果：与正常大鼠相比，乌头碱诱发心律失常时大鼠心率显著增快，Gs mRNA增高（P〈0．01）；针刺“内关”穴可有效改善心率，降低Gs mRNA（P〈0．01）。结论：心律失常可能和G蛋白信号转导障碍有关，G蛋白在针刺“内关”穴对心律失常的调节中有重要作用。

Objective： To explore the mechanism of electroacupuncture （EA） of “Neiguan”（PC- 6） in relieving tachyarrhythmia in rats. Methods： Forty Wistar rats were randomly divided into normal control, model, PC-6, and non-aoupoint groups, with 10 cases in each group. Tachyarrhythmia model was established by sublingual venous injection of 0.002% Aconitine （1 mL/kg）. EA （dense-sparse waves, 2/20 Hz, 2-3 mA） was applied to bilateral “Neiguan”（PC 6） or non-acupoints （the prominence sites of the bilateral shoulder deltoid muscles） for 10 min after successful establishment of tachyarrhythmia. The heart rates were recorded, and myocardial stirnulatory G-protein （Gs） rnRNA expression was detected by using reverse transcriptionpolymerase chain reaction （RT-PCR） method. Results： After injection of Aconitine, the heart rate of model group increased significantly compared with normal control group （P 〈 0.01 ）, and ventricular tachyarrhythmia and ventricular premature beat appeared; after acupuncture of “Neiguan”（PC 6）, the rat＇s heart recovered its normal sinus rhythm in PC-6 group, while the arrhythmia and heart rate of non-acupoint group had no marked recovery. Compared with normal control group, the heart rate of nonacupoint group increased apparently （P〈0.01）. In comparison with normal control group,the optical density （OD） values of Gs mRNA expression of model group and non-acupoint group increased significantly （ P〈 0.01 ） ; while compared with model group, the OD value of PC-6 group decreased considerably （P〈0.01）, and no significant difference was found between model and nonacupointgroup in OD values （P〉0.05）. It suggested that EA could downregulate the expression of Gs mRNA. Conclusion： EA of “Neiguan”（PC 6） can correct Aconitine induced increase of heart rate and tachyarrhythmia which is related to its effect in reducing the upregulated expression of Gs mRNA in rats with tachyarrhythmia.