Effects of chronic amiodarone therapy on L-type calcium current recovery and action potential duration of rabbit ventricular myocytes
10.3760/cma.j.issn.0253-3758.2009.06.012
- VernacularTitle:胺碘酮慢性作用对兔心室肌细胞L型钙通道电流和跨壁动作电位相关性研究
- Author:
Xiao-Jing ZHAO
1
;
Dong-Lin GUO
;
Ying WU
;
Teng-Xian LIU
;
Gan-Xin YAN
Author Information
1. 西安交通大学医学院附属第二医院
- Keywords:
Amiodarone;
Calcium channels;
Action potentials
- From:
Chinese Journal of Cardiology
2009;37(6):528-531
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of chronic amiodarone therapy on L-type calcium current recovery and action potential duration of rabbit ventriculat myoeytes.Methods Healthy rabbits duration(APD)was recorded Hnder isolated arterially laerfused left ventricular wedge preparation,then single myocytes were isolated using enzyme digestion.L-type calcium current recovery(time constant,τ)were determined by fitting data with monoexponential.τ/APD90 were compared in ceHs treated with saline,amioderone and sotalol(3×10-5 mmol/L).Results In chronic amiodarone treated myocytes,τ[(164±8)ms vs.(98±)ms,P＜0.05],APD90[(321±12)ms vs.(220±10)ms,P＜0.05]and τ/APD90 (0.51±0.03 vs.0.44±0.03,P＜0.05)were significantly increased than those in control myocytes.Sotalol significantly increased τ[(128±7)ms vs.(98±8)ms,P＜0.05]and ADP90[(405±13)ms vs.(220±10)ms,P＜0.05]while reduced the τ/APD90(0.32±0.05 vs.0.44±0.03,P＜0.05)compared to control myocytes.Conclusion The differential effect of amiodarolle and sotalol on ventricular myocytes τ/APD90 ratio might be responsible for the safety profile of these two drugs.
