The effect of nicotinic acid on the depressant action of ethanol and pentobarbital.
The effect of nicotinic acid (NA) on sleeping time induced by a single dose of ethanol or pentobarbital was studied in rats. It was found that sleeping time was markedly reduced by NA in a dose-dependent manner. The effect was observed when NA was administered 10 min before or after ethanol or pentobarbital, but not when given 60 min in advance. NA did not affect the rate of ethanol elimination measured up to 5 hr after ethanol administration. Rats pretreated with NA 60 min before ethanol slept longer than controls. This latter effect was not observed with pentobarbital. These observations, together with the known lack of effect of high liver NAD+ levels on ethanol metabolism and the rather stable NAD+ concentration in brain cells, suggest that the effect of NA on sleeping time is not mediated by an increase in ethanol metabolism in liver or by NAD+ or NAD+-dependent reactions in brain. Our results are consistent with a direct action of NA, or some rapidly formed derivative, on a structure or process associated with brain cell functions or membranes.
Department of Biochemistry, School of Medicine, University of Puerto Rico, San Juan.
C M
CM
Basilio
A
A
Toro
J
J
Bernstein
L
L
Yojay
D000818:Animals; D001921:Brain / Q000187:drug effects*; D003864:Depression, Chemical; D000431:Ethanol / Q000037:antagonists & inhibitors* / Q000097:blood; D005260:Female; D009525:Niacin / Q000494:pharmacology*; D010424:Pentobarbital / Q000037:antagonists & inhibitors*; D051381:Rats; D012890:Sleep / Q000187:drug effects
D009525:Niacin; D000431:Ethanol; D010424:Pentobarbital