兔右室流出道心肌细胞动作电位及钠钙交换尾电流特性  

The properties of action potential and sodium-calcium exchange tail current of rabbit right ventricular outflow tract myocytes

作　　者：王焱[1,2] 林晨晖[1,2] 李源[1,2] 刘泰槰[3] 肖国胜[1,2] 常贺[1,2] 黄卫斌[1,2] 叶涛[1,2] 巩燕[1,2] 

机构地区：[1]福建医科大学教学医院 [2]厦门大学附属医院厦门心脏中心,福建厦门361004 [3]北京大学生命科学学院生理学及生物物理学系,北京100871

出　　处：《中国心脏起搏与心电生理杂志》2011年第6期527-531,共5页Chinese Journal of Cardiac Pacing and Electrophysiology

基　　金：厦门市卫生局资助项目(No.A0000258)

摘　　要：目的研究兔右室流出道(RVOT)心肌细胞动作电位及钠钙交换尾电流(INCX,tail)相关特性,探讨源于RVOT室性心律失常的发生机制。方法采用全细胞膜片钳技术记录兔右室(RV)游离壁和RVOT心肌细胞的动作电位,在不更换细胞及电极内液情况下连续记录INCX,tail,对比分析两者动作电位和INCX,tail特性。结果兔RVOT心室肌细胞动作电位复极时程(APD)的变异程度大于RV游离壁心肌细胞。在RVOT心肌细胞记录到早期后除极及显著延长的APD。动作电位显著延长及后除极的RVOT心肌细胞所对应的INCX,tail到达峰值时程较动作电位正常的细胞延迟,并且电流强度大于RV游离壁对照组心肌细胞(P<0.05)。结论 RVOT心肌细胞APD变异程度大,而且APD显著延长的RVOT细胞INCX,tail到达峰值时程延迟及相应电流显著增大,这是RVOT部位好发触发活动的重要机制。Objective To explore the electrophysiological basis of arrhythmogenesis in right ventricular outflow tract （RVOT） myocytes of rabbit heart. The prope.rties of action potential and sodium-calcium exchange tail current（INCX,tail ） in rabbit RVOT cells were observed. Methods Patch-clamp technique was used to measure INCX,tail and action potential in single myocytes obtained by enzymatic dispersion of rabbit ventricle. Results Marked variability of action potential repo- larization was observed in rabbit RVOT cardiomyocytes. The events of early afterdepolarization （EAD） and marked action potential duration（APD） extension were recorded in RVOT ceils. The peak of INCX,tail was delayed significantly in marked APD extension RVOT ceils compared to RV free wall cells, and the amplitude of INCX,tail in the former was larger than the latter ones （P 〈 0.05）. Conclusion In rabbit RVOT cardiomyocytes, prolonged APD might be the induction factor of delayed afterdeporization and EAD genesis. Under this precondition, the late-peaking and larger amplitude of INCX,tail in RVOT cells might play pivotal role in the mechanism of RVOT arrhythmogenesis.

关 键 词：电生理学 右室流出道 触发机制 钠钙交换电流 动作电位 

分 类 号：R331.38[医药卫生—人体生理学]