Involvement of dopamine receptors in the antipsychotic profile of )eticlopride

The present study was performed to assess the effects exerted by the dopamine (DA) D-2/D-3 antagonist (-) eticlopride on rodent behavioral models considered to be predictive of antipsychotic activity, namely, antagonism toward DA agonist-induced stereotyped behavior (SB), and ketamine- and cocaine-induced hypermotility. (-) Eticlopride (10-50 mu g/kg) dose-dependently inhibited SB elicited by SND 919 (10 mg/kg), CQP 201-403 (0.5 mg/kg), and 7-OH-DPAT (5 mg/kg); moreover, it significantly counteracted the hypermotility induced in rats and mice by ketamine(5 and 10 mg/kg). When (-) eticlopride was injected before cocaine(15 mg/kg) either acutely or subchronically administered in male rats, it also potently antagonized the hypermotility typically induced by the drug. These results are discussed in the light of putative D-2/D-3 receptor involvement, and are considered as predictive of antipsychotic potential.