人心房颤动不同演变阶段L型钙电流重构的特征  

Remodeling of L-type calcium current of atrial myocytes during the development of human atrial fibrillation

作　　者：吴钢[1] 黄从新[1] 江洪[1] 唐其柱[1] 黄峥嵘[2] 谢强[2] 唐艳红[1] 王腾[1] 

机构地区：[1]武汉大学人民医院心内科,武汉430060 [2]厦门市第一医院心内科

出　　处：《临床心血管病杂志》2005年第11期641-644,共4页Journal of Clinical Cardiology

基　　金：国家自然科学基金资助(No:30050004)

摘　　要：目的:以人心房肌细胞为研究对象,观察心房颤动(Af)不同演变阶段,L型钙电流(IL-Ca)的重构特征。方法:标本取自风湿性心脏病并发二尖瓣狭窄及二尖瓣关闭不全接受换瓣手术患者的右心耳心肌,酶消化法分离出单个心肌细胞后,采用全细胞膜片钳技术记录ICa,L并分析其通道动力学特性。结果:共取15例患者的心肌标本,根据有无Af及Af的持续时间分为3组:对照组即窦性心率(SR)组4例,阵发性Af(PAf)组6例,慢性Af(CAf)组5例。SR、PAf和CAf组IL-Ca电流密度分别为-(7·83±0·51)、-(6·17±0·71)和-(3·68±0·40)pA/pF,组间比较,PAf组显著低于SR组(P<0·05);CAf组显著低于SR和PAf组(P<0·01);3组I-V曲线的形状无改变。3组激活曲线的半数激活电压分别为-(1·1±0·06)、-(2·7±0.09)、-(2.9±0.21)mV;激活曲线斜率因子分别为(7.7±1.1)、-(7.9±1.2)、-(8.1±0.9)mV,组间比较均差异无统计学意义。3组失活曲线的半数失活电压分别为-(23.6±0.5)、-(26.4±1.1)、-(21.9±1.3)mV;失活曲线斜率因子值分别为(6.9±0.4)、(6.0±0.6)、(6.5±0.4)mV,组间比较均差异无统计学意义。3组失活后恢复曲线的时间常数(τ)分别为(28.4±2.6)、(29.8±2.3)、(45.8±5.3)ms,PAf组与SR组比较差异无统计学意义;CAf组与SR组和PAf组相比显著增大(P<0·05),曲线右移。结论:在Af的演变过程中,IL-Ca电流密度呈进行性下降的趋势;在PAf阶段,IL-Ca的通道动力学无显著变化,CAf阶段其失活后恢复时间延长。Objective：To study the changes of L-type calcium current （IL-C8） of human atrial myocytes during the development of atrial fibrillation （Af）. Method： Myocardium samples were obtained frqm the right auricular appendage of patients with rheumatic heart disease combined with mitral valve stenosis and mitral valve incompetence. Single atrial cells were isolated using an enzyme dispersion technique. IL-C8 was recorded using the whole cell configuration of voltage clamp techniques and its kinetic properties were analyzed. Result： Myocardium samples of 15 patients were studied, 4 males and 11 females, aged 29-43 years, averaged （35.5±4.9） years. According to cardiac rhythm, 15 patients were divided into three groups： four in the controlled group defined as sinus rhythm （SR） group, six in the paroxysmal atrial fibrillation （PAf） group and five in the chronic atrial fibrillation （CAf） group. The current densities of IL-C8 in PAf group was significant lower than that in SR group [-（6.17±0.71） vs -（7.83±0.51）pA/pF, （ P 〈0.05）] and the current densities of IL-C8 in CAF group was significant lower than those in SR and PAF groups [- （3.68±0.40）pA/pF vs - （6.17±0.71）pA/pF, - （7.83±0.51）pA/pF, （ P 0. 05）]. The half-maximum activation voltage of activation curves （V1/2 ,act） in the three groups were - （1.1 ± 0. 06）, - （2.7±0.09）, - （2.9±0.21）mV respectively. The slop factors of activation curve （κact） were （7.7± 1. 1）, - （7.9±1.2）, - （8.1±0.9）mV respectively. The half inactivation-maximum voltage （V1/2 ,inact） of inactivation curves in the three groups were -（23.6±0.5）, - （26.4±1.1）, - （21.9± 1.3） respectively. The slop factors of inactivation curve （κinact） in the three groups were （6.9±0.4）, （6.0_±0.6）, （6.5±0.4）mV respectively. The time constant （τ） of recovery from inactivation in three groups were （28.4±2.6）, （29.8±2.3）, （45. 8±5.3）ms respectively, and the latte

关 键 词：心房颤动 钙通道 L型钙电流 

分 类 号：R541.7[医药卫生—心血管疾病]