Involvement of noradrenergic system in a remarkably rapid tongue clonus produced by acute hypnotic doses of ethanol in Fischer F344 rats.
Ethanol (2.95 g/kg, IP) eliminated the righting reflex and induced vigorous tongue clonus spontaneously or following tactile tongue stimulation in Fischer F344 rats. Responses normally lasted 30-60 min, and was reinstated by tactile stimulation in those cases where it subsided quickly. Sub-hypnotic (1.95 g/kg) or high (3.95 g/kg) doses failed to elicit clonus, even after tactile stimulation. A lipophilic alpha 1-adrenergic agonist (St 587) promptly initiated tongue clonus in rats treated with a 3.95 g/kg dose of ethanol. Prazosin, a selective alpha 1-adrenergic antagonist, blocked clonus, while the dopamine selective antagonist pimozide failed to modify this response. We infer an alpha 1-adrenergic effect in which norepinephrine is released by ethanol.
Menon
M K
MK
Psychopharmacology Research Laboratory, Veterans Administration Medical Center, Sepulveda, CA 91343.
Lloyd
R L
RL
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D003000:Clonidine / Q000031:analogs & derivatives / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology*; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D009132:Muscles / Q000187:drug effects; D009638:Norepinephrine / Q000502:physiology*; D010868:Pimozide / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D014059:Tongue / Q000187:drug effects*
D006993:Hypnotics and Sedatives; C030655:St 587; D010868:Pimozide; D000431:Ethanol; D003000:Clonidine; D009638:Norepinephrine; D011224:Prazosin