The effects of flunarizine and cinnarizine on apomorphine induced stereotyped behavior in rats

Apomorphine, a selective dopamine receptor agonist is known to induce stereotyped behavior in rats. We studied the effect of Flunarizine (FZ) and Cinnarizine (C2) on apomorphine induced stereotyped behavior in rats. Fz at a dose of 25, 50, or 100 μmol/kg or CZ at a dose of 100, 500, or 2000 μmol/kg were given orally to rats, followed by administration of apomorphine at a dose of 2 mg/kg intraperitoneally, after an interval of 2 hours. Subsequently, the stereotyped behavior of the rats was observed over a period of 60 minutes. FZ caused a marked decrease in the intensity of the stereotypy induced by apomorpine in a dose-dependent manner. CZ also had a suppressive effect on the stereotypy but to a lesser degree than FZ. These results indicate that FZ is more potent than CZ as a CNS dopamine receptor blocker.