Interactions of 7-[3-(4-[2,3-dimethylphenyl]piperazinyl)-propoxy]-2(1H)-quinolinone binding in rat striatum: effects of lesions.
7-[3-(4-[2,3-Dimethylphenyl]piperazinyl)propoxy]-2(1H)-quinolinone (OPC-4392), a presynaptic dopamine autoreceptor agonist and postsynaptic D-2 receptor antagonist (Yasuda et al., Life Sci. 42: 1941-1954, 1988), was studied for its binding characteristics at 3H-SCH 23390-labeled dopamine D-1 receptors and 3H-spiperone-labeled dopamine D-2 receptors in rat striatum. The binding affinity of OPC-4392 for 3H-spiperone-labeled D-2 receptors was 500 times higher than for 3H-SCH 23390-labeled D-1 receptors. 6-Hydroxydopamine lesions of striatum and high-frequency current lesions of medial forebrain bundle did not affect the competition of OPC-4392 for 3H-spiperone binding. Kainic acid lesions of striatum significantly changed the one-site model fit to a two-site model fit of the competition curve of OPC-4392 for 3H-spiperone binding, suggesting that OPC-4392 competed with 3H-spiperone binding differently for postsynaptic dopamine D-2 receptors and for presynaptic dopamine autoreceptors.
Zhang
X
X
Department of Pharmacology, Hiroshima University School of Medicine, Japan.
Nakata
Y
Y
Kikuchi
T
T
Segawa
T
T
D000818:Animals; D001552:Benzazepines / Q000378:metabolism*; D001667:Binding, Competitive / Q000187:drug effects; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D015259:Dopamine Agents / Q000494:pharmacology*; D006892:Hydroxydopamines; D066298:In Vitro Techniques; D007608:Kainic Acid; D008297:Male; D008474:Medial Forebrain Bundle / Q000502:physiology; D016627:Oxidopamine; D010879:Piperazines / Q000494:pharmacology*; D015363:Quinolones / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013134:Spiperone / Q000378:metabolism*
D001552:Benzazepines; D015259:Dopamine Agents; D006892:Hydroxydopamines; D010879:Piperazines; D015363:Quinolones; C054574:OPC 4392; D013134:Spiperone; D016627:Oxidopamine; D007608:Kainic Acid