Potent modulation of neuronal nicotinic acetylcholine receptor-channel by ethanol.
Controversies remain over which ion channels are the most sensitive to ethanol. We have found that ethanol potently modulates the neuronal nicotinic acetylcholine receptor-channel at micromolar concentrations with an EC50 of 88.5 microM, which is significantly lower than most values previously reported for other ion channels. Prolonged application of ethanol accelerated the decay phase of acetylcholine-induced currents, caused single-channels to open in bursts, and shortened the mean open time, all of which reflect increased receptor desensitization. However, ethanol slowed the decay phase of the current induced by a brief application of acetylcholine, which may indicate that ethanol manifests its action by causing an increase in the affinity of the receptor for acetylcholine. These results suggest that neuronal nicotinic acetylcholine receptors may be important target sites of ethanol, particularly in the early stages of ethanol intoxication.
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, Chicago, IL 60611, USA.
K
K
Nagata
G L
GL
Aistrup
C S
CS
Huang
W
W
Marszalec
J H
JH
Song
J Z
JZ
Yeh
T
T
Narahashi
D000435:Alcoholic Intoxication / Q000378:metabolism / Q000523:psychology; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004557:Electric Organ / Q000187:drug effects / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000187:drug effects*; D016716:PC12 Cells; D018408:Patch-Clamp Techniques; D051381:Rats; D011978:Receptors, Nicotinic / Q000187:drug effects*; D014101:Torpedo / Q000378:metabolism*
D002492:Central Nervous System Depressants; D007473:Ion Channels; D011978:Receptors, Nicotinic; D000431:Ethanol