参麦注射液对AMI大鼠左心室流出道自律细胞电生理的影响

Effect of Shenmai injection on electrophysiology of pacemaker cells in left ventricular outflow tract of rats with AMI

目的研究参麦注射液对急性心肌缺血(acute myocardial ischemia,AMI)大鼠左心室流出道慢反应自律细胞动作电位的影响。方法冠状动脉结扎法复制AMI大鼠模型,参麦注射液腹腔注射治疗7 d。采用标准玻璃微电极细胞内记录技术,记录并分析参麦注射液和0.9%氯化钠溶液治疗后AMI大鼠左心室流出道自律细胞的最大舒张电位(MDP)、0相除极幅度(APA)、0相最大除极速度(Vmax)、4相自动除极速度(VDD)、复极50%(APD50)和90%(APD90)的时间以及自发放电频率(RPF)。结果 0.9%氯化钠溶液组较正常对照组VDD和RPF明显下降,APA、Vmax减小,而APD90明显增加(P<0.01);参麦组与正常对照组比较,对照水平Vmax也减小(P<0.05),而VDD、RPF、APA差异无统计学意义(P>0.05)。结论 AMI大鼠左室流出道自律细胞电生理活性明显降低,参麦注射液具有改善流出道自律细胞电生理的作用。

Objective To observe the effect of Shenmai injection on electrophysiology of pacemaker cells in left ventricular outflow tract of rats with acute myocardial ischemia （AMI）.Methods The rat models with AMI were established by ligation of anterior descending branch of coronary artery , then the rats were treated by peritoneal injectiong with Shenmai injection for 7 days.The conventional intracellular microelectrode technique was used to record action potentials of pacemaker cells in left ventricular outflow tract after Shenmai injection or physiological saline injection,respectively.The indexes included amplitude of action potential （APA）,maximal rate of depolarization （ Vmax） ,velocity of diastolic depolarization of phase 4 （ VDD） ,rate of pacemaker firing （ RPF） , duration of 50% and 90% repolarization （ APD50 and APD90 ） .Results The VDD and RPF0 in 9% sodium chloride solution group were significantly decreased ,as compared with those in control group ,and APA and Vmax were also decreased,however,APD90 was obviously increased （ P 〈0.01）.As compared with that in Shenmai injection group,Vmax in control group was significantly decreased （ P 〈0.05）,however,there were no significant differences in VDD,RPF,APA between the two groups （ P 〉0.05）.Conclusion The electrophysiological activityof pacemaker cells in left ventricular outflow tract of rats with AMI is significantly decreased ,however, Shenmai injection can improve cardiac function and prevent left ventricular remodeling in rats after AMI .