[Behavioral changes induced by repeated administration of mazindol, an anorexiant, in rats]

Behavioral changes in locomotor activity and stereotyped behaviors induced by daily administration (for 7 days) of mazindol (5 and 10 mg/kg, po) were compared with those induced by methamphetamine (10 mg/kg) in rats. On day 1, mazindol increased locomotor activity, which was enhanced by daily administrations. Stereotyped behaviors were also induced by mazindol, which became more marked following daily administrations. Methamphetamine markedly increased stereotyped behavior rather than locomotor activity on day 1, and the effects were not enhanced by daily administrations. The increased locomotor activity and stereotyped behaviors caused by mazindol and methamphetamine were markedly reduced by the dopamine receptor antagonist pimozide (0.1-0.4 mg/kg, ip) in a dose-dependent manner. These results suggest that repeated mazindol administration enhances locomotor-stimulant and stereotypy-producing effects, which are mediated by the central dopaminergic system.