Qi Xiao-Yan, Zhang Zhi-Xiong, Cui Qi-Qi, Shi Wei-Bin, Xu You-Qiu
Department of Physiology, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2004 Feb;20(1):24-8.
To study the effect of ginkgolide B from Ginkgo leave on action potential (AP), L-type calcium current (I(Ca) - L) and delayed rectifier potassium current (I(K)) in normal and ischemic guinea pig ventricular myocytes.
With the standard microelectrode technique to record action potential and whole-cell variant patch-clamp technique to record calcium and potassium current.
(1) Under normal condition, ginkgolide B shortened APD and had no effect on RP, AP and V(max). Ginkgolide B also increased I(K) in a concentration dependent manner and had no significant effect on I(Ca) - L (2) Under ischemia condition, it was observed that shortening of APD, APA, decrease V(max) and depolarization of RP was induced by ischemia, but ginkgolide B could attenuate above--mentioned changes. (3) Under ischemia condition, I(Ca) - L and I(K) were inhibited, perfusion with ischemia solution containing ginkgolide B could reverse the decrease of I(Ca) - L and I(K).
Ginkgolide B had protective effect on ischemic myocardium to prevent ischemic arrhythmia.
研究银杏叶中银杏内酯B对正常及缺血豚鼠心室肌细胞动作电位（AP）、L型钙电流（I(Ca)-L）和延迟整流钾电流（I(K)）的影响。
采用标准微电极技术记录动作电位，采用全细胞变异膜片钳技术记录钙电流和钾电流。
（1）正常情况下，银杏内酯B缩短动作电位时程（APD），对静息电位（RP）、动作电位（AP）和最大动作电位上升速率（V(max)）无影响。银杏内酯B还以浓度依赖方式增加I(K)，对I(Ca)-L无显著影响。（2）缺血情况下，观察到缺血可导致APD、动作电位幅度（APA）缩短，V(max)降低及RP去极化，但银杏内酯B可减弱上述变化。（3）缺血情况下，I(Ca)-L和I(K)受到抑制，用含银杏内酯B的缺血溶液灌注可逆转I(Ca)-L和I(K)的降低。
银杏内酯B对缺血心肌具有保护作用，可预防缺血性心律失常。
