title: Effects of Resibufogenin and Cinobufagin on voltage-gated potassium channels in primary cultures of rat hippocampal neurons.
abstract: Outward delayed rectifier potassium channel and outward transient potassium channel have multiple important roles in maintaining the excitability of hippocampal neurons. The present study investigated the effects of two bufadienolides, Resibufogenin (RBG) and Cinobufagin (CBG), on the outward delayed rectifier potassium current (IK) and outward transient potassium current (IA) in rat hippocampal neurons. RBG and CBG have similar structures and both were isolated from the venom gland of toad skin. RBG inhibited both IK and IA, whereas CBG inhibited IK without noticeable effect on IA. Moreover, at 1 μM concentration both RBG and CBG could alter some channel kinetics and gating properties of IK, such as steady-state activation and inactivation curves, open probability and time constants. These findings suggested that IK is probably a target of bufadienolides, which may explain the mechanisms of bufadienolides' pathological effects on central nervous system.
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian, Liaoning 116024, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Hao
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Bao
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: An
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Rong-Guo
authors.initials: RG
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Bi
authors.forename: He-Shuang
authors.initials: HS
authors.lastname: Wang
authors.forename: Chang-Sen
authors.initials: CS
authors.lastname: Sun
authors.forename: Ji-Wen
authors.initials: JW
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
mesh_terms: D000664:Amphibian Venoms / Q000494:pharmacology*; D000818:Animals; D002018:Bufanolides / Q000494:pharmacology*; D056547:CA1 Region, Hippocampal / Q000166:cytology; D002478:Cells, Cultured; D008564:Membrane Potentials / Q000187:drug effects; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000664:Amphibian Venoms; D002018:Bufanolides; D015221:Potassium Channels; C005734:bufogenin; C002471:cinobufagin