肥厚心室肌钠钙交换体的表达水平对其电重构的影响研究  

Study of enhanced Na^+-Ca^(2+) exchanger expression that might contribute to the alteration of myocardial elecerophysiological characters due to short-term pacing in hypertrophied myocardium

作　　者：于厚志[1] 杨庆[1] 陈茂[1] 邓珏琳[1] 黄德嘉[1] 

机构地区：[1]四川大学华西医院

出　　处：《山东医药》2005年第20期9-11,共3页Shandong Medical Journal

基　　金：国家自然科学基金资助课题(39970303)

摘　　要：目的观察短时刺激对左心室肥厚模型心室肌电生理特性的影响,研究钠钙交换体在其中的作用。方法将15只纯种日本大耳白兔随机分为环缩组和对照组。环缩组手术环缩腹主动脉构建左心室肥厚模型,对照租仅游离出腹主动脉,不予结扎。8周后应用心脏电刺激单相动作电位记录技术测定两组心电生理参数。用免疫印迹方法定量心肌钠钙交换体。结果环缩组心脏重量/体重增加了32%。快速刺激后,环缩组心尖部心肌有效不应期明显延长,平均延长20ms(P<0.01);而对照组延长不明显,平均延长8ms(P>0.05)。环缩组钠钙交换体蛋白量增加了52%,快速刺激引起的心尖部有效不应期的延长量与钠钙交换体表达水平明显相关(r=0.73)。结论肥厚心室肌钠钙交换体的表达水平明显上调,此与其快速刺激后有效不应期的明显延长相关,可能诱发室性心律失常。Objective ： To determine whether there was enhanced Na^＋-Ca^2＋ exchanger expression that might contribute to the alteration of myocardial electrophysiological characters due to short-term pacing in hypertrophied myocardium. Methods .. Rabbits were randomized to constricted group（n = 8） and control group（n=7）. Left ventricular hypertrophy was induced in rabbit by abdominal aortic constriction. 8 weeks after feeding,the electrophysiological parameters were recorded by the monophasic action potential recording techniques. The Na^＋-Ca^z＋ exchanger protein （120kd） was quantitated by western-blot analysis. Results：The heart-to-body weight ratio was increased by 32% in constricted rabbits. Effective refractory period after rapid stimulation was lengthened significantly in constricted group, in average 20ms （P〈0. 01）, while in control group, it＇s 8ms.Western blot showed a 52 % increase in Na^＋-Ca^2＋ exchanger protein in constricted roup. The increase of effective refractory period correlated directly with the relative amount of Na^＋-Ca^2＋ exchanger protein significantly,r= 0. 73. Conclusion ..The upregulated Na^＋-Ca^2＋ exchanger protein expression level in hypertrophied myocardium correlates directly with the increase of effective refractory period, which may induce ventricular arrhythmias.

关 键 词：左心室肥厚 有效不应期 单相动作电位 钠钙交换体 

分 类 号：R541.6[医药卫生—心血管疾病] R331.3[医药卫生—内科学]