Ascorbic acid inhibits [3H]SCH-23390 binding to striatal dopamine D1 receptors.
The present study describes the inhibition of [3H]SCH-23390 binding to striatal dopamine D1 receptors in the presence of ascorbic acid. Specific [3H]SCH-23390 binding was maximally inhibited by 0.1 mM ascorbic acid. As determined by Scatchard analysis the binding in the presence of 0.01, 0.1, or 10 mM ascorbic acid was consonant with non-competitive inhibition with a 26%, 38%, or 19% decrease, respectively, in the maximal number of binding sites; the affinity of these binding sites was not affected. Inhibition of [3H]SCH-23390 binding by ascorbic acid was reversible; striatal homogenates incubated with 0.1 mM ascorbic acid and subsequently washed free of ascorbic acid had the same Scatchard parameters as untreated preparations.
Wiener
H L
HL
Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, Ward's Island, New York 10035.
Lajtha
A
A
Sershen
H
H
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D001552:Benzazepines / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D011869:Radioligand Assay; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D017447:Receptors, Dopamine D1
D001552:Benzazepines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D001205:Ascorbic Acid