【摘要】 目的研究小檗碱对大鼠心室肌细胞膜短暂外向钾电流(Ito)的影响,探讨小檗碱在离子通道水平的药理作用机制。方法用急性酶解法分离大鼠心室肌细胞,应用膜片钳全细胞记录技术,观察不同浓度的小檗碱对Ito的影响。结果小檗碱(1,3,10,30,100,300μmol/L)可浓度依赖性地降低Ito,半数抑制浓度(IC50)为40.21μmol/L,30μmol/L小檗碱可使Ito电流-电压曲线下移,但不改变曲线形状。小檗碱使Ito失活曲线向负电位方向变化,半数失活电压减小;对激活曲线无明显影响,未改变Ito激活特性。结论小檗碱可浓度依赖性地阻滞大鼠心室肌细胞的Ito。更多还原

【Abstract】 Objective To investigate the effects of berberine on the transient outward potassium currents(I_to) in isolated cardiomyocytes of rat.Methods The single ventricular myocytes of rats were obtained by enzymatic dissociation.I_to was recorded by using whole cell patch clamp technique.Results Berberine（1,3,10,30,100,300 μmol/L）reduced I_to in a concentration-dependent manner.IC₅₀ was 40.21 μmol/L.The current-voltage curve moved downward,but the shape did not change.Berberine 30 μmol/L shifted the inactivation curve of I_to to more negative potential.However,it did not affect the activation curve of I_to.Conclusions Berberine inhibits I_to in a concentration-dependent manner.更多还原