Voluntary ethanol consumption decreases after the inactivation of central acetaldehyde by d-penicillamine.
Acetaldehyde, the first metabolite of ethanol, may mediate some ethanol-induced effects. Previous research in our laboratory has shown that D-penicillamine, an inactivation agent for acetaldehyde, is effective in decreasing locomotor stimulation and conditioned place preference induced by ethanol in mice. In the present study, the effects of D-penicillamine on the voluntary consumption of ethanol were assessed. Male rats were offered ethanol under restricted access, without food or water deprivation. Daily availability of ethanol was limited to a 15-min period in the home cages. When the response for 10% ethanol was stable, rats received an intraperitoneal (IP) injection of D-penicillamine (0, 25, 50 or 75 mg/kg) over a 5-day period, given 30 min before exposure to ethanol. In a second study we determined the specificity of D-penicillamine effects (50 mg/kg) on voluntary sucrose consumption (3%). Another study was conducted to evaluate whether IP D-penicillamine (50 mg/kg) alters taste reactivity responses. In the final experiment, rats were treated with intracerobroventricular (ICV) infusions of D-penicillamine (75 microg) for 5 days before drinking ethanol or sucrose. D-Penicillamine was found to reduce ethanol intake in a dose-dependent manner. Sucrose consumption was also affected by this thiol amino acid. We also demonstrated that D-penicillamine produced changes in the ingestive and flavor properties of sucrose and ethanol, measured by means of a taste reactivity test. When D-penicillamine was administered ICV, only voluntary ethanol consumption was modified. These findings indicate that the central inactivation of acetaldehyde blocks ethanol intake in rats, and suggest that acetaldehyde plays a key role in the motivational properties of ethanol.
Font
Laura
L
Area de Psicobiología, Universitat Jaume I, Castelló, Spain.
Aragon
Carlos M G
CM
Miquel
Marta
M
D000079:Acetaldehyde / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000284:Administration, Oral; D000428:Alcohol Drinking / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D002492:Central Nervous System Depressants / Q000008:administration & dosage / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects*; D004336:Drug Antagonism; D000431:Ethanol / Q000008:administration & dosage / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010396:Penicillamine / Q000008:administration & dosage / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D012646:Self Administration; D013395:Sucrose / Q000008:administration & dosage; D013649:Taste / Q000187:drug effects
D002492:Central Nervous System Depressants; D000431:Ethanol; D013395:Sucrose; D010396:Penicillamine; D000079:Acetaldehyde