苄基四氢巴马汀对豚鼠和大鼠心室肌细胞钾电流的影响。

Effects of benzyltetrahydropalmatine on potassium currents in guinea pig and rat ventricular myocytes.

作者信息

Li Yang, Fu Li-Ying, Yao Wei-Xing, Xia Guo-Jin, Jiang Ming-Xing

机构信息

Department of Cardiology, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan 430030, China.

出版信息

Acta Pharmacol Sin. 2002 Jul;23(7):612-6.

PMID:12100754

Abstract

AIM

To investigate the effects of benzyltetrahydropalmatine (BTHP) on rapidly activating component (I(Kr)), slowly activating component (I(Ks)) of delayed rectifier potassium current, inward rectifier potassium current (I(K1)), and transient outward potassium current (I(to)) in single ventricular myocytes.

METHODS

Whole-cell patch clamp technique was used to record ionic currents.

RESULTS

(1) BTHP 30 micromol/L reduced I(Kr) and I(Kr,tail) by 31 %+/-4 % and 36 %+/-5 % (n=6, P <0.01), respectively and inhibited I(Ks) and I(Ks,tail) by 40 %+/-6 % and 45 %+/-5 % (n=7, P <0.01), respectively. I(Kr) and I(Ks) were blocked by BTHP 1-100 micromol/L in a concentration-dependent fashion (IC50 value was 13.5 micromol/L and 95 % confidence limit: 11.2-15.8 micromol/L for I(Kr), 9.3 micromol/L and 95 % confidence limit: 7.8-11.8 micromol/L for I(Ks), respectively). (2) BTHP 5 micromol/L inhibited I(to) by 63 %+/-6 % (n=6, P <0.01). BTHP 1-100 micromol/L reduced I(to) in a concentration-dependent manner (IC50 value was 3.6 micromol/L and 95 % confidence limit: 2.9-4.3 micromol/L). (3) BTHP 200 micromol/L did not affect I(K1).

CONCLUSION

BTHP inhibited I(Kr), I(Ks), and I(to), but not I(K1). The antiarrhythmic effects of BTHP may be mainly due to its blockade on potassium channels.

摘要

目的

研究苄基四氢巴马汀（BTHP）对单个心室肌细胞延迟整流钾电流的快速激活成分（I(Kr)）、缓慢激活成分（I(Ks)）、内向整流钾电流（I(K1)）和瞬时外向钾电流（I(to)）的影响。

方法

采用全细胞膜片钳技术记录离子电流。

结果

（1）30 μmol/L的BTHP分别使I(Kr)和I(Kr,tail)降低31%±4%和36%±5%（n = 6，P <0.01），并分别抑制I(Ks)和I(Ks,tail) 40%±6%和45%±5%（n = 7，P <0.01）。1 - 100 μmol/L的BTHP以浓度依赖性方式阻断I(Kr)和I(Ks)（I(Kr)的IC50值为13.5 μmol/L，95%置信区间：11.2 - 15.8 μmol/L；I(Ks)的IC50值为9.3 μmol/L，95%置信区间：7.8 - 11.8 μmol/L）。（2）5 μmol/L的BTHP使I(to)抑制63%±6%（n = 6，P <0.01）。1 - 100 μmol/L的BTHP以浓度依赖性方式降低I(to)（IC50值为3.6 μmol/L，95%置信区间：2.9 - 4.3 μmol/L）。（3）200 μmol/L的BTHP对I(K1)无影响。