Baclofen decreases somatic expression of mecamylamine-precipitated nicotine withdrawal in mice

VARANI ANDRÉS P; BONELLI CLAUDIA G; BALERIO GRACIELA

Buenos Aires. Argentina

Congreso; XXXIX Reunión anual de la Sociedad Argentina de Farmacología Experimental; 2007

Sociedad Argentina de Farmacologia Experimental

Nicotine (NIC) is one of the active components of tobacco and play a major role in tobacco addiction. The aims of the present study were: a) to evaluate the possible role of GABAB receptor in NIC physical dependence; b) to analyze the neurochemical variations in various brain regions of mice during NIC withdrawal syndrome and its prevention with baclofen (BAC, GABAB receptor agonist). Swiss-Webster albino mice received NIC (2.5 mg/kg, sc) four times daily, for 7 days. To precipitate NIC abstinence, dependent mice were injected with the nicotine antagonist mecamylamine (MEC, 2 mg/kg, ip) 1h after the last dose of NIC on the 8th day. A second group of dependent mice received BAC (2 mg/kg, ip) before MEC- precipitated abstinence. Somatic signs were measured for 30 min. The levels of dopamine, serotonin and its metabolites were determined by HPLC in the striatum, cortex and hippocampus. BAC pre-treatment decreased the incidence of some NIC withdrawal signs, such as wet-dog-shakes (p