Determination of dopamine D(4) receptor density in rat striatum using PB12 as a probe.
N-[2-[4-(4-Chlorophenyl)piperazin-1-yl]ethyl]-3-methoxybenzamide (PB12), a potent and selective dopamine D(4) receptor ligand, was used as a probe for the direct determination of the dopamine D(4) receptor density in rat striatum as an alternative to the subtraction method. The experiment was performed using [(3)H]spiroperidol to label D(2), D(3) and D(4) receptors and PB12 to determine directly dopamine D(4) receptor specific binding. The determined B(max) value was 82 fmol/mg protein. The contribution of the dopamine D(4) receptor to the overall population of D(2)-like receptors was 63%; however, this value cannot be considered reliable because of the observed difference in the kinetic profiles of D(2), D(3) and D(4) receptors.
Colabufo
N A
NA
Dipartimento Farmaco-Chimico, Universidà di Bari, via Orabona 4, 70126 Bari, Italy. colabufo@farmchim.uniba.it
Berardi
F
F
Calò
R
R
Leopoldo
M
M
Perrone
R
R
Tortorella
V
V
D000818:Animals; D001549:Benzamides / Q000378:metabolism* / Q000494:pharmacology; D001667:Binding, Competitive / Q000187:drug effects; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006220:Haloperidol / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D010879:Piperazines / Q000378:metabolism* / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050638:Receptors, Dopamine D4; D013134:Spiperone / Q000378:metabolism; D013997:Time Factors; D014316:Tritium
D001549:Benzamides; C493601:Drd4 protein, rat; C115935:N-(2-(4-(4-chlorophenyl)piperazin-1-yl)ethyl)-3-methoxybenzamide; D010879:Piperazines; D017448:Receptors, Dopamine D2; D014316:Tritium; D050638:Receptors, Dopamine D4; D013134:Spiperone; D006220:Haloperidol