Inhibition of berberine on Ⅰ_(Kr), Ⅰ_(Ks) and Ⅰ_(K1) in thyroxine induced cardiomyopathic guinea pig ventricular myocytes
10.3321/j.issn:1000-5048.2009.03.011
- VernacularTitle:盐酸小檗碱对甲状腺素性豚鼠心肌病心肌细胞中Ⅰ_(Kr),Ⅰ_(Ks)和Ⅰ_(K1)的抑制作用
- Author:
Feng YU
;
Musen LIN
;
Weidong ZHANG
- Publication Type:Journal Article
- Keywords:
berberine;
thyroxine;
cardiomyopathy;
Ⅰ_(Ks);
Ⅰ_(Kr);
Ⅰ_(K1);
patch clamp techniques
- From:
Journal of China Pharmaceutical University
2009;40(3):244-249
- CountryChina
- Language:Chinese
-
Abstract:
Aim: To study the effects of berberine( Ber) on the rapidly activating component( Ⅰ_(Kr)), the slowly activating component(Ⅰ_(Ks)) of the delayed rectifier potassium current and the inward rectifier potassium current(Ⅰ_(K1)) in cardiomyopathic guinea pig ventricular myocytes. Methods: After guinea pigs were ip L-thyroxine 0. 5 mg/kg for 10 d, their hearts were cardiomyopathic. Then whole cell patch-clamp recording technique was used to observe the effect of 30 μmol/L Ber on the Ⅰ_(Kr), Ⅰ_(Ks) and Ⅰ_(K1) in cardiomyopathic guinea pig ventricular myocytes. Results: In cardiomyopathic guinea pig ventricular myocytes, Ber 30 μmol/L markedly inhibited Ⅰ_(Kr) and Ⅰ_(Ks) by 22. 8% and 29. 5% at + 10 mV and + 80 mV, respectively. The effect of Ber on Ⅰ_(Ks) was greater than that on Ⅰ_(Kr). Ber 30 μmol/L also inhibited the inward component of Ⅰ_(K1) by 29. 1% at + 120 mV, but the reverse potential of Ⅰ_(K1) was unaffected. Ber( 1-300 μmol/L) was shown to inhibit Ⅰ_(Kr) and Ⅰ_(Ks) in a concentration-dependent manner. Their IC_(50), were 76. 74 μmol/L and 55. 37 μmol/L, respectively. Conclusion: Ber inhibited Ⅰ_(Kr),Ⅰ_(Ks) and Ⅰ_(K1) in cardiomyopathic guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.
