Effects of allocryptopine on outward potassium current and slow delayed rectifier potassium current in rabbit myocardium

作     者：Yi-Cheng FU Yu ZHANG Liu-Yang TIAN Nan LI Xi CHEN Zhong-Qi CAI Chao ZHU Yang LI 

作者机构：Division of Cardiology Chinese PLA General Hospital Beijing China 

出 版 物：《Journal of Geriatric Cardiology》 (老年心脏病学杂志（英文版）)

年 卷 期：2016年第13卷第4期

页      面：316-325页

核心收录：

学科分类：0710[理学-生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 071003[理学-生理学] 

主　　题：Allocryptopine Endocardium Epicardium Midcardium Slow delayed rectifier potassium channel Transient outward potassiumcurrent 

摘      要：Objective Allocryptopine （ALL） is an effective alkaloid of Corydalis decumbens （Thunb.） Pers. Papaveraceae and has proved to be an- ti-arrhythmic. The purpose of our study is to investigate the effects of ALL on transmural repolarizing ionic ingredients of outward potassium current （Ito） and slow delayed rectifier potassium current （IKs）. Methods The monophasic action potential （MAP） technique was used to record the MAP duration of the epicardium （Epi）, myocardium （M） and endocardium （Endo） of the rabbit heart and the whole cell patch clamp was used to record/to and IKs in cardiomyocytes of Epi, M and Endo layers that were isolated from rabbit ventricles. Results The effects of ALL on MAP of Epi, M and Endo layers were disequilibrium. ALL could effectively reduce the transmural dispersion of repolarization （TDR） in rabbit transmural ventricular wall. ALL decreased the current densities of/to and IKs in a voltage and concentration dependent way and narrowed the repolarizing differences among three layers. The analysis of gating kinetics showed ALL accelerated the channel activation ofIto in M layers and partly inhibit the channel openings of/to in Epi, M and Endo cells. On the other hand, ALL mainly slowed channel deactivation of IKs channel in Epi and Endo layers without affecting its activation. Conclusions Our study gives partially explanation about the mechanisms of tmnsmural inhibition of/to and IKs channels by ALL in rabbit myocardium. These findings provide novel perspective regarding the anti-arrhythmogenesis application of ALL in clinical settings.