【摘要】 目的:研究家兔心肌肥厚时三层心肌细胞延迟整流钾电流慢激活成分异质性的改变及长期应用咪达普利（Imi）对此变化的作用。方法:缩窄兔单侧腹主动脉制备心肌肥厚模型,同时设Imi治疗组和假手术组,采用全细胞膜片箝技术记录兔心肌细胞动作电位和钾电流。结果:（1）肥厚心肌细胞的膜电容明显高于假手术组和Imi治疗组;其动作电位时程（APD）显著延长,尤其是中层细胞（M）延长最为显著;应用Imi后可逆转此延长效应;（2）肥厚心肌细胞上I_ks,tail密度均不同程度的降低,外膜和内膜细胞分别降低25.3％±2.9％和20.3％±4.7％,而M降低最为显著为38.0％±3.7％;用Imi后电流密度降低程度明显被缓解,该电流的跨室壁异质性减少。（3）在三层心肌细胞上I_kr,tail的差异不明显,且I_kr,tail密度在三组也改变较小。结论:长期应用Imi可以减少兔肥厚心肌细胞延迟整流钾电流慢激活成分的跨室壁异质性改变。更多还原

【Abstract】 AIM: To investigate the transmural heterogeneous change of slow component of delayed rectifying potassium current in rabbit left ventricular hypertrophic myocytes and the effect of long-term treatment with imidapril （Imi）. METHODS: Rabbits were divided into hypertrophy group （left ventricular hypertrophy induced by partial ligation of abdominal aorta）, Imi-treated group （surgical treatment as hypertrophy group was treated with Imi）, and Sham operated group as control. Whole-cell patch-clamp technique was used to record potassium currents. RESULTS: （1） Membrane capacitance was larger in hypertrophic cells than in sham-operated and Imi-treated cells. Action potential durations （APD） of epicardium （Epi）, midmyocardium （M）, and endocardium （Endo） were remarkably longer in hypertrophic cells than those in Imi-treated and sham-operated cells. The prolongation of APD₉₀ of M was the most pronounced in three layer myocytes of hypertrophic group. （2） The densities ofI_Ks,tail of hypertrophic cells were reduced by Epi 25.3%±2.9%, M 38.0%±3.7% and Endo 20.3%±4.7% compared with those of shamoperated cells. The decrease of I_Ks,tail density was more pronounced in M than in Epi and Endo （n=13, P<0.01 vs Epi or Endo）. （3） The density of I_Kr,tail in Imi-treated cells was not different fiom that in sham-operated cells significantly （n=10）. CONCLUSION: Imi reduced prolongation of APD and inhibited the heterogeneous change of I_Ks,tail in rabbit left ventricular hypertrophic myocytes.更多还原