马钱子碱对大鼠心室肌细胞瞬时外向钾电流的影响  

Effects of brucine on transient outward potassium current of ventricular myocytes of rats

作　　者：甘文云[1] 唐其柱[1] 王腾[1] 王蕾[1] 田青[1] 周恒[1] 郭海鹏[1] 

机构地区：[1]武汉大学人民医院心内科,湖北武汉430060

出　　处：《心脏杂志》2010年第2期172-175,共4页Chinese Heart Journal

摘　　要：目的:探讨马钱子碱(brucine)对大鼠心室肌细胞瞬时外向钾电流(transient outward potassium current,Ito)及其动力学的影响。方法:用酶解法分离大鼠单个心室肌细胞。用全细胞膜片钳技术记录不同浓度的马钱子碱可对大鼠心室肌细胞Ito的前后影响变化。结果:①马钱子碱可浓度依赖性地阻断Ito;②5μmol/L的马钱子碱可使Ito稳态激活曲线右移,V1/2由对照的(-30.7±10.2)mV变为(-27.8±5.8)mV(P<0.05);③5μmol/L的马钱子碱可使Ito稳态失活曲线左移,V1/2分别为(-41.6±1.0)mV变为(-75.0±2.8)mV(P<0.05);④5μmol/L的马钱子碱可使Ito稳态激活曲线右移失活后再恢复时间常数τ延长。结论:提示马钱子碱可以阻断Ito,对Ito的激活态和失活态均具有较高的亲和力,这些可能是其抗心律失常作用的机制。AIM： To explore the effects of brucine on transient outward potassium current （Ito） of ventricular cardiomyocytes of rats. METHODS： Single ventricular myoeytes of rats were obtained by enzymatic dissociation. The whole-cell patch-clamp recording technique was used to record the changes of Ito by different dosages of brucine. RESULTS： Brucine significantly reduced I,o in a concentrationdependent manner. Brucine at 5 μmol/L shifted the stabilized activation curve to the right and the halfpoint of actiation potential （V1/2） from （ 30. 7±10.2） mV to （ 27. 8 ±5.8） mV （n =8, P〈0. 05）. Brucine （5 μmol/L） shifted the stabilized deactivation curve to the left and the half-point of actiation potential （V1/2） from （41.6 ±1.0） mV to （75.0 ±2. 8） mV （n =8, P〈0. 05）. Brucine （5 μmol/L） significantly prolonged the recovery time. CONCLUSION： Brucine has significant inhibitive effects on Ito, which may be one of the mechanisms that underlie its antiarrhythmic effect.

关 键 词：马钱子碱 瞬时外向钾电流 全细胞膜片钳技术 心室肌细胞 大鼠 

分 类 号：R514.7[医药卫生—内科学]