Calcium enhancement of alcohol and drug-induced sleeping time in mice and rats.
Calcium injected intracerebroventricularly (IVT) at various times before a hypnotic dose of ethanol significantly enhanced the duration of sleeping time (loss of righting reflex, LRR) in mice and rats. This cation also enhanced the duration of LRR induced by t-butanol and chloral hydrate, but not that induced by sodium pentobarbital. Other cations injected IVT (manganese, cadmium, and zinc) also enhanced ethanol-induced LRR. The synergistic effects of the ionophores X537A and A23187 on calcium-enhanced LRR, and the antagonism of ethanol-induced LRR by EDTA and EGTA suggest the involvement of a membrane-associated calcium pool in the hypnotic effect of ethanol. These studies show the generality of cation enhancement of alcohol-induced sleeping time in mice and rats, and confirm earlier reports which suggested that calcium is involved with the central nervous system depressant effects of alcohols.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002412:Cations / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004357:Drug Synergism; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D007476:Ionophores / Q000494:pharmacology; D051379:Mice; D010424:Pentobarbital / Q000494:pharmacology; D051381:Rats; D012890:Sleep / Q000187:drug effects*; D014149:Tranquilizing Agents / Q000494:pharmacology
D002412:Cations; D002492:Central Nervous System Depressants; D007476:Ionophores; D014149:Tranquilizing Agents; D000431:Ethanol; D010424:Pentobarbital; D002118:Calcium