Exposure to nicotine enhances acquisition of ethanol drinking by laboratory rats in a limited access paradigm

Abstract

Observations in humans suggest that the initial use of tobacco occurs in close temporal proximity to experimentation with alcohol. There have been relatively few research reports, however, examining possible interactions between these two agents. The present experiments examined the effect of nicotine exposure on the acquisition of ethanol drinking behavior in a limited access procedure. In experiment 1, rats were presented with 1-h access to ethanol solutions of increasing concentration for a period of 20 days. Subcutaneous injections of nicotine (0.6 or 1.2 mg/kg salt) or vehicle were administered 30 min prior to each ethanol presentation. Experiment 2 used a similar method, but rats were presented with water along with ethanol during the 1-h test session. Mecamylamine, a nicotinic receptor antagonist, was administered 30 min prior to the nicotine treatment. Nicotine was seen to produce a dose-dependent increase in ethanol drinking behavior which commenced at the 5% ethanol concentration and continued at 8% and again at 10%. In the second experiment, mecamylamine was observed to block completely the nicotine-induced increase in ethanol drinking behavior. The findings suggest that exposure to nicotine can facilitate the acquisition of ethanol drinking behavior in naive rats and that this effect is mediated by nicotine's interaction at the nicotinic-cholinergic receptor.

Exposure to Nicotine in Adult, but not Adolescent, Rats Increases Alcohol Self-Administration in Adulthood

“…However, nicotine pre-treatment did not affect the consummatory aspects when animals were allowed to freely intake ethanol for 24 hours. Nicotine pre-treatment has previously shown to increase alcohol seeking in adult rodents [13,[31][32][33][34]. In accordance with our results, López-Moreno et al [35] showed an increase in ethanol selfadministration 14 days after cessation of chronic nicotine administration in adult rats.…”

Use of Caffeine-Based Products and Tobacco in Relation to the Consumption of Alcohol

“…Similarly, this was also reported for nicotine exposure on ethanol drinking in rats [20]. Thus, it would be tempting to speculate as to whether the intake of one of these substances is a primary process effecting the other consumptions.…”

“…Recently, several animal studies on the interaction of tobacco and alcohol have been published. The findings of these studies appear to support the observation that levels of ethanol intake in rats injected with nicotine are significantly elevated [17][18][19][20].…”

Nicotinic Receptors in the Brain Links between Molecular Biology and Behavior

“…For example, in the brain stimulation reward model, both drugs decrease the dose of nicotine required to lower the self-stimulation threshold (Huston-Lyons et al 1993). Conversely, prior exposure to nicotine enhances the conditioned rewarding effects of morphine (Shippenberg et al 1996), accelerates the acquisition of ethanol drinking behavior in naive rats (Smith et al 1999) and predisposes rats to self-administer a low dose of cocaine (Horger et al 1992). In the place preference paradigm, nicotine can potentiate the action of low doses of cocaine, whereas antagonism of nAChRs decreases the response to a threshold dose of cocaine ).…”