牵张刺激对乳大鼠心房肌细胞瞬时外向钾电流和内向整流钾电流的影响  

Effects of stretch on transient outward potassium and inward rectifier potassium current in cultured neonatal rat atrial myocytes

作　　者：胥亚楠[1] 杨龙[1,2] 杨天和[1] 邓春玉[3] 罗淋[1] 覃智芳[2] 唐倩[1] 杨君[1] 

机构地区：[1]贵阳医学院附属人民医院心内科,贵州贵阳550002 [2]遵义医学院第三附属医院心内科,贵州遵义563003 [3]广东省人民医院医学研究中心,广东广州510080

出　　处：《中国病理生理杂志》2014年第8期1489-1492,共4页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81060018)

摘　　要：目的:探究牵张刺激对乳鼠心房肌细胞瞬时外向钾电流(Ito)、内向整流钾电流(IK1)和动作电位时程(APD)的影响。方法:取1日龄SD乳大鼠心脏,分离、消化获得心房肌细胞。于细胞牵引装置培养24 h分组:对照组不予牵张刺激;牵张组予增加12%硅胶膜面积牵张刺激24 h。膜片钳全细胞记录方法记录细胞膜Ito、IK1和APD的变化。结果:在+60 mV刺激电压水平,牵张组Ito密度与对照组相比明显降低[(1.6±0.4)pA/pF vs(12.1±2.9)pA/pF,P<0.01]。在-120 mV刺激电压下,牵张组IK1密度较对照组增大[(-10.8±0.8)pA/pF vs(-8.8±0.9)pA/pF,P<0.01]。牵张组动作电位复极50%(APD50)和复极90%(APD90)均较对照组明显缩短[(10.5±1.4)ms vs(15.5±2.4)ms,(30.0±2.8)ms vs(56.3±3.6)ms,P<0.01]。结论:牵张刺激可降低乳大鼠心房肌细胞Ito密度,增大IK1密度,缩短APD,这可能是压力负荷增大致心房电重构的基础之一。AIM：Toinvestigatetheeffectsofmechanicalstretchontransientoutwardpotassiumcurrent（Ito）, inward rectifier potassium current （ IK1 ） and action potential duration （ APD） of cultured neonatal rat atrial myocytes . METHODS：Neonatal rat atrial myocytes were isolated and cultured on silicone sheeting with or without stretch for 24 h. The silicone membrane area was increased by 12%in stretched group.The cells without stretch served as control .Ito, IK1 and APD were recorded by the technique of whole-cell patch clamp.RESULTS：Compared with control group, Ito density in stretched myocytes was significantly reduced [（1.6 ±0.4） pA/pF vs （12.1 ±2.9） pA/pF, P〈0.01], whereas IK1 density was increased [（-10.8 ±0.8） pA/pF vs （-8.8 ±0.9） pA/pF, P〈0.01].The APDs at 50%and 90%levels of repolarization （ APD50 and APD90 ） in the stretched cells were obviously decreased than those in non-stretched cells [（10.5 ±1.4） ms vs （15.5 ±2.4） ms, （30.0 ±2.8） ms vs （56.3 ±3.6） ms, P〈0.01].CONCLUSION： Stretch stimulation leads to the reduction of Ito density, the increase in IK1 density and the shortness of APD in cultured rat atrial neonatal myocytes , which may contribute to atrial electrical remodeling induced by pressure overload .

关 键 词：牵张 心房肌细胞 膜片钳技术 钾电流 动作电位 

分 类 号：R363[医药卫生—病理学]