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目的研究腹主动脉结扎诱发大鼠肥厚心肌L-型钙电流的变化以及用氯沙坦治疗对此变化的影响.方法用结扎腹主动脉的方法诱发大鼠心肌肥厚模型.用全细胞膜片钳技术记录肥厚左心室肌细胞L-型钙电流.结果肥厚组心肌细胞膜电容(148±29 pF)明显大于假手术组(102±14 pF, P<0.01)和氯沙坦治疗组(118±27,P<0.01).肥厚组ICa,L峰值及电流密度均大于假手术组(-835±124 pA vs-1404±417 pA和-7.5±1.8 pA.pF-1vs-10.5±2.2 pA.pF-1,P<0.01).氯沙坦治疗组ICa,L峰值(-956±170 pF)及电流密度(-8.2±1.6 pA.pF-1)均比肥厚组明显减小(P<0.05).肥厚组半数激活电压(-20.6±1.0 mV)与假手术组(-15.6±1.6 mV)及氯沙坦治疗组(-17.4±1.0 mV)相比向负向移动(P<0.01).肥厚组激活曲线斜率(5.7±0.4)比假手术组(6.4±0.5)略减小(P<0.05).肥厚组半数失活电压(-27.6±1.9 mV)比假手术组(-31.4±2.2 mV)略正移(P<0.05).三组心肌失活曲线斜率无差异.结论氯沙坦(30 mg·kg-1·d-1,ig)可防止腹主动脉结扎诱发大鼠心肌细胞肥大的发生及相关的L-型钙电流的变化.“,”Objective To investigate the alterations of L-type calcium current (ICa,L) in abdominal aortic ligation-induced hypertrophied rat hearts and the effect of losartan on these alterations. METHODS Cardiac hypertrophy was induced by abdominal aortic llgation in rats. To record ICa,L, whole-cell patch-clamp technique was used. RESULTS Membrane capacitance was larger in hypertrophied cells (148±29 pF) than in sham-operated cells (102±14 pF, P<0.01) and losartan-treated cells (118±27, P<0.01). The maximal peak ICa,L was increased from -835±124 pA in sham-operated cells to -1404±417 pA in hypertrophied cells (P<0.01), the corresponding ICa,L pF (P<0.01) and -8.2±1.6 pA.pF-1 (P<0.05) respectively in losartan-treated cells. The membrane potential of half maximal activation of the hypertrophied cells (-20.6±1.0 mV) shifted to more negative potentials than sham-operated cells (-15.6±1.6 mV, P<0.01) and lorsartan-treated cells (-17.4±1.0 mV, P<0.01). The slope of the activation curve of hypertrophied cells (5.7±0.4) was decreased slightly than sham-operated cells (6.4±0.5, P<0.05). The membrane potential of half maximal inactivation of hypertrophied cells (-27.6±1.9 mV) shifted to more positive potentials than sham-operated cells (-31.4±2.2 mV, P<0.05). The slope of inactivation curves were not different in the three groups.in abdominal aortic ligation-induced hypertrophied rat hearts.