Dopamine D1- and D2-receptor interaction in turning behaviour induced by dopamine agonists in 6-hydroxydopamine-lesioned rats.
The selective dopamine D2-antagonist sulpiride potentiated contralateral circling behaviour induced by the D1-agonist CY 208-243 in rats with unilateral lesions of substantia nigra, but reduced the effects of the selective D2-agonist bromocriptine. Similarly, the D1-antagonist SCH 23390 tended to increase the effects of bromocriptine but markedly inhibited CY 208-243 induced turning. The mixed D1/D2-antagonist fluphenazine was effective in reducing circling behaviour induced by either agonist, whereas pimozide (D1/D2) inhibited only the actions of bromocriptine. These results indicate that the actions of CY 208-243 and bromocriptine are mediated via distinct but interacting receptor subtypes.
Karlsson
G
G
Preclinical Research, Sandoz Ltd., Basel, Switzerland.
Jaton
A L
AL
Vigouret
J M
JM
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D001971:Bromocriptine / Q000494:pharmacology*; D006892:Hydroxydopamines / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D016627:Oxidopamine; D010617:Phenanthridines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D013378:Substantia Nigra / Q000502:physiology; D013469:Sulpiride / Q000494:pharmacology*
D001552:Benzazepines; D006892:Hydroxydopamines; D007211:Indoles; D010617:Phenanthridines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; C054531:CY 208-243; D001971:Bromocriptine; D013469:Sulpiride; D016627:Oxidopamine