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论文类型：期刊论文

发表时间：2011-12-01

发表刊物：TOXICOLOGY IN VITRO

收录刊物：Scopus、SCIE、PubMed

卷号：25

期号：8

页面范围：1644-1653

ISSN号：0887-2333

关键字：Resibufogenin (RBG); Cinobufagin (CBG); Delayed rectifier potassium current (I(K)); Transient potassium current (I(A)); Hippocampal neurons; Patch clamp

摘要：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 (I(K)) and outward transient potassium current (I(A)) in rat hippocampal neurons. RBG and CBG have similar structures and both were isolated from the venom gland of toad skin. RBG inhibited both I(K) and I(A), whereas CBG inhibited I(K) without noticeable effect on I(A). Moreover, at 1 mu M concentration both RBG and CBG could alter some channel kinetics and gating properties of I(K), such as steady-state activation and inactivation curves, open probability and time constants. These findings suggested that I(K) is probably a target of bufadienolides, which may explain the mechanisms of bufadienolides' pathological effects on central nervous system. (C) 2011 Elsevier Ltd. All rights reserved.