title: [Effect of 17beta-estradiol on Kv2.1 current and delayed rectifier potassium current in cultured rat hippocampal neurons].
abstract: OBJECTIVE
  To study the effects of 17beta-estradiol on Kv2.1 potassium channel current and delayed rectifier potassium current (IK) in cultured rat hippocampal neurons.
  
  
  METHODS
  The effects of 17beta-estradiol on Kv2.1 channel current and IK in cultured rat hippocampal neurons were observed using the whole cell patch clamp techniques.
  
  
  RESULTS
  17beta-Estradiol was shown to reduce the amplitude of Kv2.1 current and IK in concentration-dependent manners. The IC50s of 17beta-estradiol blocking Kv2.1 and IK were 2.4 and 4.0 micromol x L(-1), respectively. 17beta-Estradiol (3 micromol x l(-1)) significantly shifted the steady-state activation and inactivation curves of Kv2.1 current to negative potentials. However, it only produced the shift of the steady-state activation curve of IK to the negative potential without effect on the steady-state inactivation of IK.
  
  
  CONCLUSIONS
  17beta-Estradiol inhibits Kv2.1 and IK of hippocampus at similar level. The inhibition of 17beta-estradiol on IK current may be partially via blocking Kv2.1 current.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Jin
authors.forename: Hai-xia
authors.initials: HX
authors.lastname: Zhang
authors.forename: Shao-feng
authors.initials: SF
authors.lastname: Xu
authors.forename: Hai-bo
authors.initials: HB
authors.lastname: Yu
authors.forename: Xiao-liang
authors.initials: XL
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D002478:Cells, Cultured; D051668:Delayed Rectifier Potassium Channels; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000166:cytology; D008297:Male; D009474:Neurons / Q000166:cytology / Q000502:physiology; D018408:Patch-Clamp Techniques; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D051669:Shab Potassium Channels
chemical_list: D051668:Delayed Rectifier Potassium Channels; C496988:KCNB1 protein, human; C496991:Kcnb1 protein, rat; D024642:Potassium Channels, Voltage-Gated; D051669:Shab Potassium Channels; D004958:Estradiol