[Effect of 17beta-estradiol on Kv2.1 current and delayed rectifier potassium current in cultured rat hippocampal neurons].
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.
Zhang
Wei
W
Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
Jin
Hong-wei
HW
Zhang
Hai-xia
HX
Xu
Shao-feng
SF
Yu
Hai-bo
HB
Wang
Xiao-liang
XL
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
D051668:Delayed Rectifier Potassium Channels; C496988:KCNB1 protein, human; C496991:Kcnb1 protein, rat; D024642:Potassium Channels, Voltage-Gated; D051669:Shab Potassium Channels; D004958:Estradiol