Evidence that striatal synthesis-inhibiting autoreceptors are dopamine D3 receptors.
The activation constants (KA; dose required to occupy 50% of receptors) for reversal of gamma-butyrolactone (GBL)-induced elevation of striatal L-3,4-dihydroxyphenylalanine (L-DOPA) levels via stimulation of presynaptic dopamine receptors were determined for apomorphine and two dopamine D3 receptor-selective agonists, quinpirole and LY163502 (quinelorane). The KA values correlated significantly with the affinities (Ki) of the agonists for the D3 (r = 0.999, P < 0.05) but not the D2 (r = -0.13) receptor, suggesting that striatal synthesis-inhibiting autoreceptors are of the D3 rather than the D2 subtype.
Meller
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E
Millhauser Laboratories, New York University School of Medicine, NY 10016.
Bohmaker
K
K
Goldstein
M
M
Basham
D A
DA
D015107:4-Butyrolactone / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D015259:Dopamine Agents / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D007980:Levodopa / Q000378:metabolism*; D011804:Quinolines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011954:Receptors, Dopamine / Q000378:metabolism*; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D013237:Stereoisomerism
D015259:Dopamine Agents; C493595:Drd3 protein, rat; D011804:Quinolines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D007980:Levodopa; D001058:Apomorphine; D015107:4-Butyrolactone; C047726:quinelorane