双(7)-他克林对非洲爪蟾卵母细胞表达的Kv4．2和Kv1．2编码钾通道的作用  

Effect of bis(7)-Tacrine on K_v4.2 and K_v1.2 Encoding Potassium Channel Expressed in Xenopus Oocytes

作　　者：余雯静[1] 聂辉[1] 袁春华[2] 李享元[1] 李之望[1] 

机构地区：[1]华中科技大学同济医学院基础医学院神经生物学系,武汉430030 [2]湖南师范大学生命科学学院,长沙410006

出　　处：《华中科技大学学报（医学版）》2008年第2期145-148,共4页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

基　　金：国家自然科学基金资助项目(No.30370456)

摘　　要：目的用非洲爪蟾卵母细胞表达之Kv4.2和Kv1.2编码的快和慢钾通道,检验双(7)-他克林对此两种通道是否有抑制作用。方法应用爪蟾卵母细胞注射mRNA进行表达,电压钳记录Kv4.2和Kv1.2钾电流(IK)。结果双(7)-他克林抑制IK(Kv4.2)和IK(Kv1.2)的IC50值分别为(0.23±0.05)μmol/L和(0.24±0.06)μmol/L。结论此种抑制效应可能与在双(7)-他克林作用下表达的Kv4.2和Kv1.2钾通道激活曲线向超极化电压方向偏移有关。Objective To examine whether bis（7） tacrine exerts a similar inhibitory effects on encoding K^＋ channels expressed in oocytes of Xenopus laevis as reported previously on rat DRG neurons. Methods Transient and sustained potassium currents were recorded using voltage-clamp techniques on oocytes Xenopus expressing Kv4.2 and Kv1. 2 mRNA. Results It has been identified that bis（7）-tacrine inhibited IK（Kv4.2） and ⅠK（Kv1.2） markedly with IC50 values of （0.23±0.05） μmol/L and （0.24±0.06） μmol/L, respectively. Conclusion The inhibition of bis（7）-tacrine on transient and sustained potassium channels was deduced to be caused by shift of activation curves for these two K^＋ channels to the hyperpolarizing direction. These results coincide very well with the phenomenon observed in native KA and KDR channels recorded in rat DRG neurons.

关 键 词：双(7)-他克林 非洲爪蟾卵母细胞 钾通道 抑制效应 

分 类 号：R338.8[医药卫生—人体生理学]