Differential inhibition by dopamine D-1 and D-2 antagonists of circling behaviour induced by dopamine agonists in rats with unilateral 6-hydroxydopamine lesions.
The selective dopamine (DA) D-1 antagonist SCH 23390 antagonized the contralateral circling behaviour induced by the DA D-1 agonist SK & F 38393 in rats lesioned unilaterally with 6-hydroxy-DA but had a 600 times weaker effect against the preferential DA D-2 agonist pergolide. The D-2 antagonists clebopride and spiroperidol had the reverse selectivity. The mixed D-1/D-2 antagonists cis(Z)-flupentixol and cis(Z)-clopenthixol blocked the circling induced by either agonist. It is concluded that circling behaviour is mediated by closely related but independent DA D-1 and D-2 receptor sites.
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001067:Appetite Depressants / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D002375:Catalepsy / Q000139:chemically induced; D003006:Clopenthixol / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D005475:Flupenthixol / Q000494:pharmacology; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology*; D008297:Male; D016627:Oxidopamine; D010479:Pergolide; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013239:Stereotyped Behavior / Q000187:drug effects*
D014150:Antipsychotic Agents; D001067:Appetite Depressants; D001549:Benzamides; D001552:Benzazepines; D004873:Ergolines; D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D010479:Pergolide; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D016627:Oxidopamine; D003006:Clopenthixol; D000661:Amphetamine; D005475:Flupenthixol; C014417:clebopride