论文部分内容阅读
利用全细胞膜片钳技术测定大鼠心室肌细胞的Ito,研究苄基四氢巴马汀 (BTHP)对大鼠心室肌瞬时外向钾电流 (Ito)的影响 .结果显示 ,5 .0 μmol·L- 1BTHP可以降低Ito,使Ito幅值从 (13.8± 2 .2 )pA·pF- 1降至 (5 .1± 1.4 )pA·pF- 1(P <0 .0 1) .在 1～ 10 0μmol·L- 1范围内BTHP的作用呈浓度依赖性 ,IC50 为3.6μmol·L- 1,该药不改变Ito电流 电压曲线的形状 ,而使电流幅值减少 .5 .0 μmol·L- 1BTHP使稳态激活曲线右移 ,半激活电压 (V1/2 )从 (- 6.8±0 .2 )mV移至 (- 1.5± 0 .1)mV ,但曲线斜率基本不变 .BTHP对失活曲线影响不大 ,5 .0 μmol·L- 1BTHP使通道失活后恢复时间常数从 (75± 19)ms延长为(119± 2 1)ms(P <0 .0 1) .结果说明 ,BTHP浓度依赖地阻滞大鼠心室肌细胞的Ito.
Whole-cell patch-clamp technique was used to determine the Ito of rat ventricular myocytes, and the effect of benzyltetrahydropalmatine (BTHP) on the transient outward potassium current (Ito) of rat ventricular myocardium was investigated. The results showed that 5.0 μmol·L - 1BTHP decreased Ito and decreased Ito amplitude from (13.8 ± 2.2) pA · pF-1 to (5.1 ± 1.4) pA · pF-1 (P <0.01) The effect of BTHP in the concentration of 0μmol·L-1 was concentration-dependent with IC50 of 3.6μmol·L-1. The drug did not change the shape of Ito current-voltage curve, but decreased the current amplitude.5.0μmol·L-1BTHP The steady state activation curve shifted to the right, and the half activation voltage (V1 / 2) shifted from (- 6.8 ± 0.2) mV to (-1.5 ± 0.1) mV, but the slope of the curve remained unchanged. And the recovery time constant after inactivation of channel was prolonged from (75 ± 19) ms to (119 ± 2 1) ms (P <0.01) by 5 μmol·L-1BTHP.The results showed that the concentration of BTHP Dependently block Ito in rat ventricular myocytes.