Bai Chang-Xi, Sunami Akihiko, Namiki Takao, Sawanobori Tohru, Furukawa Tetsushi
Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda, Tokyo 101-0062, Japan.
Eur J Pharmacol. 2003 Aug 22;476(1-2):35-44. doi: 10.1016/s0014-2999(03)02174-5.
Panax ginseng is a folk medicine with various cardiovascular actions; however, its underlying mechanisms of action are not well known. In the present study, we examined the effects of ginseng and its main component, ginsenoside Re, on action potentials and membrane currents recorded from isolated guinea pig ventricular myocytes with the whole-cell patch clamp technique. Ginseng (1 mg/ml) shortened the action potential duration in a rate-dependent manner. Ginseng depressed the L-type Ca2+ current (I(Ca-L)) in a mode of both tonic block and use-dependent block, and enhanced the slowly activating component of the delayed rectifier K+ current (I(Ks)). Ginsenoside Re 3 microM exhibited similar electrophysiological effects to those of 1 mg/ml ginseng, but of slightly smaller magnitude. Inhibition of I(Ca,L) and enhancement of I(Ks) by ginsenoside Re appear to be one of the main electrophysiological actions of ginseng in the heart, although contributions from other ingredients should be considered.
人参是一种具有多种心血管作用的民间药物；然而，其潜在的作用机制尚不清楚。在本研究中，我们采用全细胞膜片钳技术，研究了人参及其主要成分人参皂苷Re对分离的豚鼠心室肌细胞动作电位和膜电流的影响。人参（1mg/ml）以速率依赖性方式缩短动作电位时程。人参以强直阻滞和使用依赖性阻滞两种方式抑制L型钙电流（I(Ca-L)），并增强延迟整流钾电流（I(Ks)）的缓慢激活成分。3 microM人参皂苷Re表现出与1mg/ml人参相似的电生理效应，但幅度略小。人参皂苷Re对I(Ca,L)的抑制和对I(Ks)的增强似乎是人参在心脏中的主要电生理作用之一，尽管应考虑其他成分的贡献。
