Characterization of [125I]SCH 23982 binding in human brain: comparison with [3H]SCH 23390.
We studied binding of [125I]SCH 23982 in two regions of human brain, the caudate and the dorsolateral prefrontal cortex. Binding characteristics of [125I]SCH 23982 and of the non-iodinated tritiated analogue, [3H]SCH 23390, were compared. In caudate, binding of [125I]SCH 23982 was consistent with binding to D1 dopamine receptors while in frontal cortex, [125I]SCH 23982 bound mostly to serotonergic 5HT2 receptors. In contrast to [3H]SCH 23390, no evidence of binding of [125I]SCH 23982 to D1 receptors could be found in human frontal cortex. This indicates that iodination of SCH 23390 induces a decrease in its relative D1 versus 5HT2 selectivity that prohibits the use of [125I]SCH 23982 to label D1 receptors in human cortex.
Laruelle
M
M
Neuropathology Section, IRP, NIMH Neuroscience Center, Saint Elizzbeths, Washington, DC.
Sidhu
A
A
Casanova
M F
MF
Weinberger
D R
DR
Kleinman
J E
JE
D000328:Adult; D001552:Benzazepines / Q000031:analogs & derivatives* / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011954:Receptors, Dopamine / Q000378:metabolism; D017447:Receptors, Dopamine D1
C049558:8-iodo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol; D001552:Benzazepines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D007650:Ketanserin