银杏苦内酯B对缺血豚鼠心室肌动作电位、L-型钙电流和延迟整流钾电流的作用  

THE EFFECT OF GINKGOLIDE B ON ACTION POTENTIAL,L-TYPE CALCIUM CURRENT AND DELAYED RECTIFIER POTASSIUM CURRENT IN ISCHEMIC GUINEA PIG VENTRICULAR MYOCYTES

作　　者：祁小燕[1] 张志雄[1] 崔启启[2] 施渭彬[2] 徐有秋[2] 

机构地区：[1]上海中医药大学生理教研室,上海200032 [2]上海第二医科大学生理教研室,上海200025

出　　处：《中国应用生理学杂志》2004年第1期24-28,共5页Chinese Journal of Applied Physiology

基　　金：上海市教委资助课题 (99G18)

摘　　要：目的 :研究银杏苦内酯B对正常和缺血心室肌细胞动作电位 (actionpotential,AP) ,L 型钙电流 (L typecalciumcurrent,ICa-L)、延迟整流钾电流 (DelayedRectifierCurrennt,IK)的影响。方法 :用常规细胞内微电极方法记录豚鼠心室肌细胞动作电位 ,用全细胞膜片钳技术记录游离心室肌细胞离子流。结果 :①在生理条件下 ,银杏苦内酯B可缩短心室肌细胞动作电位时程 (actionpotentialduration ,APD) ,但对AP其他参数无影响 ,银杏苦内酯B可增大IK,呈浓度依赖性 ,但对ICa-L无显著作用 ;②在缺血条件下 ,APD50 、APD90 明显缩短 ,RP、APA减小 ,Vmax减慢 ,而银杏苦内酯B则可延缓和减轻缺血所引起上述参数的变化 ;3.在缺血条件下 ,IK 和ICa -L均受到抑制 ,但加入银杏苦内酯B后可逆转缺血所造成这两种离子流的减小。结论 :银杏苦内酯B可对抗心肌缺血所引起的心肌电生理的变化 ,提示银杏苦内酯B可预防心律失常的发生。Aim: 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. Methods: With the standard microelectrode technique to record action potential and whole-cell variant patch-clamp technique to record calcium and potassium current. Results: 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. ③Under 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. Conclusion: Ginkgolide B had protective effect on ischemic myocardium to prevent ischemic arrhythmia.

关 键 词：银杏苦内酯B 缺血 豚鼠 心室肌 动作电位 L-型钙电流 延迟整流钾电流 

分 类 号：Q463[生物学—生理学] R331.31[医药卫生—人体生理学]