Gating kinetics of Shaker K+ channels are differentially modified by general anesthetics
Gating kinetics of Shaker K+ channels are differentially modified by general anesthetics
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DOI：
10.1152/ajpcell.1998.275.4.c1009
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发表时间：
1998-10-01
影响因子：
5.5
通讯作者：
Correa, AM
中科院分区：
文献类型：
--
作者：
Correa, AM
The ShakerB K+ channel was used as a model voltage-gated channel to probe the interaction of volatile general anesthetics with gating mechanisms. The effects of three anesthetics, chloroform (CHCl3), isoflurane, and halothane, were studied using recombinant native and mutant Shaher channels expressed in Xenopus oocytes. Gating currents and macroscopic ionic currents were recorded with the cut-open oocyte voltage-clamp technique. The effects of CHCl3 and isoflurane on gating kinetics of noninactivating mutants were opposite, whereas halothane had no effect. The effects on ionic currents were also agent dependent: CHCl3 and halothane produced a reduction of the macroscopic conductance, whereas isoflurane increased it. The results indicate that the gating machinery of the channel is mostly insensitive to the anesthetics during activation until near the open state. The effects on the conductance are mainly due to changes in the transitions in and out of the open state. The data give support to direct protein-anesthetic interactions. The magnitude and nature of the effects invite reconsideration of Shaker-like K+ channels as important sites of action of general anesthetics.
