【摘要】 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-1 vs －0.5±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。更多还原

【Abstract】 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 ligation 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 density was increased from －7.5±1.8 pA·pF-1 to －10.5±2.2 pA·pF-1 (P<0.01), while they were reduced to －956±170 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. Conclusion Treatment with losartan (30 mg·kg-1·d-1, ig) prevented the cell enlargement and the alterations of ICa,L in abdominal aortic ligation-induced hypertrophied rat hearts.更多还原