- 作者: Chern-En Chiang a, Hsiang-Ning Luk b, Ling-Lan Chen a, Tsui-Min Wang c, Philip Yu-An Ding a
- 作者服務機構: a Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital and National Yang-Ming University, b Department of Anesthesiology, Chang-Gung Memorial Hospital, and c Graduate Institute of Medical Science, Taipei Medical University, Taipei, Taiwan
- 中文摘要: --
- 英文摘要: Genistein is an isoflavone with potent inhibitory activityon protein tyrosine kinase. Previous studies have shownthat genistein has additional effects, among which thedirect blocking effects on various ionic channels haverecently been disclosed. Using whole-cell voltage clampand current clamp techniques, we demonstrate that mi-cromolar concentrations of genistein dose-dependentlyand reversibly inhibit the inward rectifying K current,and depolarize the resting membrane potential, resultingin abnormal automaticity in guinea pig ventricular myo-cytes. Interestingly, another potent tyrosine kinase inhib-itor, tyrphostin 51, did not produce the same inhibitoryeffect, while the inactive analogue of genistein, daidzein,had a similar blocking effect. We suggest that genisteindirectly blocks the inward rectifying K current in ventric-ular myocytes, and one should be cautious of its pro-arrhythmic effect in clinicaluse.
- 中文關鍵字: --
- 英文關鍵字: Genistein, Daidzein, Tyrosine kinase, Guinea pig, Voltage clamp, Inward rectifying potassium current