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Inhibition of KCNQ1‐4 potassium channels expressed in mammalian cells via M 1 muscarinic acetylcholine receptors
Author(s) -
Selyanko A. A.,
Hadley J. K.,
Wood I. C.,
Abogadie F. C.,
Jentsch T. J.,
Brown D. A.
Publication year - 2000
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.2000.t01-2-00349.x
Subject(s) - chinese hamster ovary cell , muscarinic acetylcholine receptor , potassium channel , chemistry , receptor , acetylcholine receptor , inward rectifier potassium ion channel , acetylcholine , biophysics , oxotremorine , ion channel , patch clamp , muscarinic acetylcholine receptor m2 , stimulation , microbiology and biotechnology , biology , biochemistry , endocrinology
KCNQ1‐4 potassium channels were expressed in mammalian Chinese hamster ovary (CHO) cells stably transfected with M 1 muscarinic acetylcholine receptors and currents were recorded using the whole‐cell perforated patch technique and cell‐attached patch recording. Stimulation of M 1 receptors by 10 μ m oxotremorine‐M (Oxo‐M) strongly reduced (to 0–10%) currents produced by KCNQ1‐4 subunits expressed individually and also those produced by KCNQ2+KCNQ3 and KCNQ1+KCNE1 heteromers, which are thought to generate neuronal M‐currents ( I K,M ) and cardiac slow delayed rectifier currents ( I K,s ), respectively. The activity of KCNQ2+KCNQ3, KCNQ2 and KCNQ3 channels recorded with cell‐attached pipettes was strongly and reversibly reduced by Oxo‐M applied to the extra‐patch membrane. It is concluded that M 1 receptors couple to all known KCNQ subunits and that inhibition of KCNQ2+KCNQ3 channels, like that of native M‐channels, requires a diffusible second messenger.