BUPROPION INDUCES SNIFFING - A POSSIBLE DOPAMINERGIC MECHANISM

The effect of bupropion, an antidepressant drug, on sniffing behaviour was examined in rats. Animals treated intraperitoneally (i.p.) with d ifferent doses of bupropion (5-40 mg/kg) showed sniffing behaviour in a dose-related manner. Pretreatment of animals (i.p.) with the dopamin e antagonists SCH 23390 (0.025-0.1 mg/kg) or sulpiride (12.5-50 mg/kg) decreased the sniffing induced by bupropion. Reserpine pretreatment ( 2.5 mg/kg, i.p., 18 h) alone and in combination with alpha-methyl-p-ty rosine (AMPT; 250 mg/kg, i.p.) also reduced the behaviour produced by the drug. The alpha-adrenoceptor phenoxybenzamine (5 and 10 mg/kg, i.p .) and the beta-adrenoceptor antagonist propranolol (5 and 10 mg/kg, i .p.) administered 60 min prior to bupropion did not affect the drug's effect on sniffing. Propranolol alone, however, induced sniffing. The antimuscarinic atropine (5 and 10 mg/kg, i.p.) administered 30 min pri or to bupropion increased the bupropion response. Atropine alone induc ed vigorous sniffing. It is concluded that bupropion induced sniffing through a dopaminergic mechanism.