Effect of nicotine on sniffing induced by dopaminergic receptor stimulation

Effects of nicotine on sniffing induced by amphetamine and apomorphine have been tested in rats. Intraperitoneal (i.p.) administration of nicotine (0. 5 and 1 mg/kg), amphetamine (1-6 mg/kg) or apomorphine (0.1-1 mg/kg) induce d sniffing. Nicotine (0.25-1 mg/kg) potentiates sniffing induced by ampheta mine (1 mg/kg). Nicotine (1 mg/kg) also potentiates the response induced by different doses (0.1-1 mg/kg) of apomorphine. Atropine induced sniffing an d increased the response of both amphetamine and nicotine. Higher doses of hexamethonium decreased the sniffing response induced by amphetamine and th e response induced by combination of amphetamine and nicotine. Sulpiride re duced the response induced by nicotine or amphetamine plus nicotine, while SCH23390 reduced normal sniffing behaviour of the animals and sniffing indu ced by either amphetamine or amphetamine plus nicotine. The data may indica te that nicotinic receptor mechanism(s) may be involved in the sniffing ind uced by dopaminergic receptor stimulation. (C) 2000 published by Elsevier S cience B.V.