Effects of single and long-term administration of sulpiride on open-field and stereotyped behavior of rats.
1. The effects of single (3.0 to 180.0 mg/kg) and long-term (up to 90.0 mg/kg) administration of sulpiride on open-field and apomorphine-induced stereotyped behavior of rats were studied. 2. When animals were studied 30 min after ip sulpiride administration, locomotion and rearing frequencies in the open-field or apomorphine effects were not modified in a dose-dependent and consistent way by the single sulpiride administration. 3. In relation to control values, a significant decrease in apomorphine-induced stereotyped behavior was observed when rats were injected with a single sulpiride dose 2.5, 5.0, 7.5 and 10.0 h before the dopaminergic agonist. 4. Withdrawal from long-term ip sulpiride administration (up to 90.0 mg/kg per injection, twice daily for 57 days) induced a significant increase in all parameters of activity recorded in the open-field, and the responsiveness to apomorphine was also augmented in sulpiride-withdrawn rats. 5. These results suggest that sulpiride, a benzamide drug that differs from classic neuroleptic agents by producing fewer extrapyramidal side effects, also induces supersensitivity of central dopaminergic receptors.
Frussa-Filho
R
R
Departamento de Fisiologia, Faculdade de Medicina de Marflia, SP, Brasil.
Palermo-Neto
J
J
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D013239:Stereotyped Behavior / Q000187:drug effects*; D013469:Sulpiride / Q000008:administration & dosage*
D011954:Receptors, Dopamine; D013469:Sulpiride; D001058:Apomorphine