Effect of ethanol on tracheal potassium channels reconstituted into bilayer lipid membranes.
We examined the effect of ethanol on single potassium channels derived from plasma membranes of bovine tracheal smooth muscles. The observed potassium channels had a conductance of 296 +/- 31 pS (mean +/- S.D.) in symmetrical 250 mmol/l KCl solutions, and exhibited a voltage- and Ca2+-dependence similar to BKCa channels. Ethanol at 50, 100 and 200 mM concentrations increased the probability of open potassium channels to 112 +/- 5, 127 +/- 7 and 121 +/- 13% (mean +/- S.E.M.), respectively. It is suggested that increased activity of the BKCa channels by ethanol hyperpolarizes the plasma membrane and thus may contribute to relaxation of tracheal smooth muscle.
Kominková
V
V
Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava.
Magova
M
M
Mojzisová
A
A
Maleková
E
E
Ondrias
K
K
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry / Q000502:physiology; D004553:Electric Conductivity; D000431:Ethanol / Q000494:pharmacology*; D015640:Ion Channel Gating / Q000187:drug effects; D008051:Lipid Bilayers / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D014132:Trachea / Q000737:chemistry* / Q000502:physiology
D008051:Lipid Bilayers; D015221:Potassium Channels; D000431:Ethanol; D011189:Potassium Chloride; D002118:Calcium