氟卡尼对兔左室壁心肌细胞兴奋性的不同影响  

The different effects of flecainide on the excitability of myocardial cells in rabbit left ventricular

作　　者：李佳娜[1,2] 舒娟[1] 杨琳[1] 王丹[1] 刘萌[1] 史梦[1] 严干新 

机构地区：[1]西安交通大学第一附属医院心内科,教育部环境与疾病相关基因离子通道病重点实验室,陕西西安710061 [2]榆林市第二医院心内科,陕西榆林719000 [3]Main Line Health Heart Center

出　　处：《中国心脏起搏与心电生理杂志》2015年第2期147-150,共4页Chinese Journal of Cardiac Pacing and Electrophysiology

基　　金：国家自然科学基金资助项目(编号:81070162)

摘　　要：目的观察钠通道阻滞剂氟卡尼对兔左室壁内、外膜侧心肌细胞电兴奋活动的影响。方法采用冠状动脉灌注兔左室楔形组织块标本，用银一氯化银电极记录跨壁心电图，浮置玻璃微电极记录内、外膜侧心肌细胞动作电位，观察正常情况及细胞外高钾情况下，氟卡尼（10ixmol／L）对跨壁心电图和内、外膜侧心肌细胞动作电位兴奋性的影响。结果氟卡尼对内、外膜侧心肌细胞动作电位兴奋性的影响不同；正常台式液情况下，加入氟卡尼后，当刺激频率加快至2．8—3．8Hz时，9例标本中有7例出现外膜侧动作电位脱失的现象；细胞外高钾情况下，加入氟卡尼后，刺激频率为1．3—2．1Hz时，9例标本中有7例出现外膜侧动作电位脱失的现象。结论本实验观察到，兔左室内、外膜侧心肌细胞兴奋性存在差异，经氟卡尼干预后，二者之间兴奋性的差异表现明显；当静息膜电位减小，细胞膜电位去极化，心肌细胞兴奋性降低时，阻断Na通道可使内、外膜侧心肌细胞兴奋性的差异更显著。Objective Observe the effect of flecainide ,sodium channel blocker, on rabbit left ventricular about its elec- trical excitation activity of epicardial and endocardium myocardial cells. Methods Using the wedge tissue specimen of rab- bit left ventricular and recording transmural electrocardiogram （ECG） with a silver - silver chloride electrode, recording ac- tion potential of myocardial cells with floating glass microelectrode, we observed the effects of flecainide （ 10 txmol/L） on the action potential excitability of eRicardium （Epi） and endocardium （Endo） myocardial cells under normal circumstances and case of increasing extracellular potassium concentration. Results The effects of flecainide on the action potential excitabili- ty of myocardial cells were different between Epi and Endo. Under normal circumstances, after adding flecainide, when stim- ulation frequency accelerated to 2.8-3.8 Hz, in all nine preparations,we observed seven preparations＇epicardial action poten- tial droping out. Increasing extracellular potassium concentration, the same phenomenon was observed seven in nine prepara- tions when stimulation frequency accelerated to 1.3-2.1 Hz. Conclusion Our experimental results suggest, the excitabili- ty of myocardial cells is different between Epi and Endo of rabbit left ventricle, the differences between the two performance obviously after flecainide intervention. When the resting membrane potential decreases, the membrane potential depolarized, decreasing the excitability of myocardial ceils, then blocking Na channel ,the differences between Epi and Endo are more obviously.

关 键 词：电生理学 氟卡尼 左心室楔形标本 兴奋性 动作电位 

分 类 号：R33-4[医药卫生—人体生理学] R331.38[医药卫生—基础医学]