Effects of ethanol on nicotine-induced conditioned place preference in C57BL/6J mice.
It has been shown that small doses of ethanol (<or= 1.0 g/kg) may antagonize the discriminative stimulus properties of nicotine. The aim of the present study was to evaluate whether ethanol could antagonize nicotine's rewarding effects in the conditioned place preference procedure. For comparison, effects of ethanol on nicotine-induced seizures were assessed. Male C57BL/6J mice were used in all experiments. Lower doses of nicotine (0.3 and 0.6 mg/kg, s.c.) induced significant conditioned place preference, while higher doses (0.9 and 1.2 mg/kg) induced neither conditioned place preference nor conditioned place aversion. In the following experiments, ethanol (0.5 or 1.0 g/kg, i.p.) was administered 5 min before 0.3 mg/kg nicotine. Ethanol did not antagonize nicotine-induced conditioned place preference. Contrary to our hypothesis, a non-significant (p = 0.07) enhancement of nicotine-induced place preference conditioning was observed in mice pre-treated with 1.0 g/kg ethanol. Both doses of ethanol (0.5 and 1.0 g/kg) suppressed seizures elicited by a high dose of nicotine (6.0 mg/kg). Ethanol totally eliminated clonic-tonic component of nicotine-induced seizures. Maximal blood ethanol levels after i.p. administration of 0.5 or 1.0 g/kg ethanol exceeded 60 and 115 mg%, respectively. The present results may indicate that the rewarding and seizure-inducing effects of nicotine are differentially modulated by clinically relevant concentrations of ethanol in mice.
Korkosz
Agnieszka
A
Department of Pharmacology, Institute of Psychiatry and Neurology, Sobieskiego 9 St., PL-02957 Warsaw, Poland.
Zatorski
Pawel
P
Taracha
Ewa
E
Plaznik
Adam
A
Kostowski
Wojciech
W
Bienkowski
Przemyslaw
P
D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002492:Central Nervous System Depressants / Q000097:blood / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D012201:Reward
D002492:Central Nervous System Depressants; D018722:Nicotinic Agonists; D000431:Ethanol; D009538:Nicotine