药物性和缺血性心律失常模型心肌M3受体表达差异与心律失常的关系

Alteration of cardiac M_3 receptor and its relationship with arrhythmias in drug-induced and ischemia-induced arrhythmic models

目的:探讨乌头碱等药物性和缺血性心律失常模型心肌M3受体的变化及其与心律失常的关系。方法:40只大鼠随机分为4组,正常对照组、乌头碱、氯化钡和缺血组。除正常对照组外,其余各组分别注射乌头碱、氯化钡及结扎冠脉诱发大鼠心律失常,记录1h心电图的变化。Western blotting检测心肌M3受体的表达(24h)。结果:各组均可诱发心律失常,乌头碱组心律失常的持续时间较其余2个模型组明显延长。Western blotting显示,各组模型大鼠心肌M3受体的表达均上调,分别为正常组的2.3、1.4和1.3倍,其中乌头碱组心肌M3受体的含量明显升高。心肌M3受体蛋白的表达和心律失常的持续时间呈正相关关系。结论:心律失常能诱导心肌M3受体的表达上调,且不同心律失常模型心肌M受体上调的幅度不同,其机制可能和心律失常的严重程度呈正相关关系。

AIM： To investigate the alteration of cardiac M3 receptor and its relationship with arrhythmias in various arrhythmic models. METHODS ： Forty Wistar rats were randomly divided into 4 groups ： control, aconitine, BaCl2 and ischemia. In the later three groups, arrhythmias were induced by treatment with aconitine, BaCl2 and coronary artery occlusion, respectively. The arrhythmias were recorded for 1 h. Western blotting was then used to detect M3 receptor con- tents. RESULTS ： Arrhythmias were all induced in each group. In aconitine - induced arrhythmias, duration of arrhythmias and arrhythmia score were significantly increased than those in other two model groups. Western blotting showed that the expression of M3 receptor upregnlated 2. 3, 1.4 and 1.3 folds respectively, more abundant in various arrhythmic groups than that in the normal control. Moreover, M3 receptor expression in aconitine group increased significantly than that in BaCl2 and ischemia group. The arrhythmias and M3 receptor protein expressions in myocytes were positively correlated. CONCLUSION ： Arrhythmias upregnlate the expression of cardiac M3 receptor. The upregnlating levels of M3 receptor proteins diverge strikingly in different arrhythmic models. It is probably that the diversity of increase in M3 receptor is positive related to severity of ventricular arrhythmias.