K+ channels close more slowly in the presence of external K+ and Rb+
- 4 June 1981
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 291 (5814), 427-429
- https://doi.org/10.1038/291427a0
Abstract
The voltage-sensitive gates regulating the permeability of ionic channels in nerve membrane were originally thought to be insensitive to the concentration1 and species2,3 of readily permeant cations. In contrast, blocking cations—tetraethyl-ammonium4, N-methylstrychnine5 or pancuronium6—when present in the inner end of potassium or sodium channels, hinder closing of the gates by a ‘foot in the door’ effect. Recent work on acetylcholine channels has clearly shown that the lifetime of the conducting state is prolonged by certain species of permeant cations7,8. In this case, the presence of a permeant ion near the inner end of the channel is thought to prevent closing. Somewhat similar effects have recently been reported for the K+ channels of nerve membrane9–11. We report here unequivocal evidence that the permeant cations K+ and Rb+ when present externally, slow the closing of K+ channels in squid axon, supporting the view that gating is indeed sensitive to the presence and species of permeant cations in the channels.This publication has 13 references indexed in Scilit:
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