Locomotor effects of amperozide. Antagonism of amphetamine-induced locomotor stimulation

Amperozide given subcutaneously (0.25 mg/kg) depressed amphetamine-induced locomotor activity by 40%. In the absence of amphetamine (1.5 mg/kg), this dose of amperozide had no effect on locomotor activity during the 60 min test period. Amperozide (0.1-1 mg/kg) dose-dependently decreased the locomotor activity of mice as measured in motron boxes. Only doses of amperozide greater than 0.25 mg/kg resulted in statistically significant (p less than 0.05) decreases in motor activity. Pretreatment of mice with flumazenil (10 mg/kg p.o., 30 min) or bicuculline (2 mg/kg i.p., 10 min) had no effect on amperozide (1 mg/kg)-induced hypomotility. These doses of the drugs had no effect per se. These results suggest that dopaminergic mechanisms might be involved in the amperozide-induced hypomotility.