摘要
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.
To investigate the effects of benzyltetrahydropalmatine (BTHP) on the transient outward potassium currents(I to), I to were recorded in rat single ventricular myocytes by using whole cell patch clamp technique. The results showed that 5.0 μmol·L -1 BTHP significantly reduced I to from (13.8±2.2)pA·pF -1 to (5.1±1.4)pA·pF -1(P<0.01,n=6). BTHP 1-100 μmol·L -1 reduced I to in a concentration-dependent manner, IC 50 was 3.6 μmol·L -1. Furthermore, 5.0 μmol·L -1 BTHP shifted the half-point of activation potential (V 1/2)from (-6.8±0.2 )mV to (-1.5±0.1)mV. BTHP increased the recovery time constant (τ) from(75±19)ms to (119±21)ms (P<0.01,n=6). The results indicate that BTHP inhibits I to in a concentration-dependent manner.
出处
《中国药理学与毒理学杂志》
CAS
CSCD
北大核心
2001年第5期358-361,共4页
Chinese Journal of Pharmacology and Toxicology
关键词
抗心律失常药
苄基四氢巴马汀
心肌
钾电流
膜片钳技术
anti-arrhythmia agents
benzyltetrahydropalmatine
myocardium
potassium current
patch clamp technique
