牵张刺激对乳大鼠心房肌细胞瞬时外向钾电流和动作电位的影响  

Effects of stretch on transient outward potassium and action potential of cultured atrial neonatal myocytes

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

机构地区：[1]贵州省人民医院心内科,贵阳医学院附属人民医院,贵阳550002 [2]遵义医学院第三附属医院 [3]广东省人民医院

出　　处：《临床心血管病杂志》2014年第7期636-639,共4页Journal of Clinical Cardiology

基　　金：国家自然科学基金项目(No:81060018)

摘　　要：目的:探究牵张刺激对乳大鼠心房肌细胞瞬时外向钾电流(Ito)和动作电位时程(APD)的影响。方法:1d龄SD乳鼠,采用胰酶消化法分离获得心房肌细胞。于细胞牵引装置培养24h分组:对照组:不予牵张刺激;牵张组:牵张增加12%硅胶膜面积24h。采用膜片钳全细胞记录方法记录两组细胞膜Ito和APD的变化。结果:在+20^+60mV刺激电压水平,牵张组Ito电流密度与对照组相比明显降低[(1.6±0.4)pA/pF∶(12.1±2.9)pA/pF,P<0.01,n=9];牵张组动作电位复极50%(APD50)、复极90%(APD90)均明显缩短[(10.5±1.4)ms∶(15.5±2.4)ms,(30.0±2.8)ms∶(56.3±3.6)ms;均P<0.01,n=9]。结论:牵张刺激可降低乳鼠心房肌细胞Ito电流密度,缩短APD,这可能是压力负荷增大致心房电重构的基础之一。Objective：To investigate stretch on transient outward potassium current（Ito）and action potential（AP）of cultured atrial neonatal myocytes.Method：Neonatal rat atrial cardiomyocytes were isolated and cultured on silicone sheeting for 24 hours.One group with silicone membrane area increased by 12% was cultured for 24 hours,samples without stretched were regarded as controls.Ito and AP were recorded by whole-cell patch clamp technique.Result：With the＋20-＋60clamp potential,compared with control group,the density of Ito was significantly reduced in stretched myocytes[（1.6±0.4）pA/pF vs（12.1±2.9）pA/pF,P0.01,n=9].The AP duration（APD）at 50% and 90%level of repolarization（APD50and APD90）of stretched group were visibly shorter than control group[（10.5±1.4）ms vs（15.5±2.4）ms,（30.0±2.8）ms vs（（56.3±3.6）ms,P0.01,respectively].Conclusion：The stretch can reduce density of Ito and shorten the APD of atrial myocytes of rat,which is attributed to atrial electrical remodeling induced by pressure overload.

关 键 词：牵张 心房肌细胞 全细胞膜片钳技术 瞬时外向钾电流 动作电位 

分 类 号：R541.4[医药卫生—心血管疾病]