title: [3H]nemonapride and [3H]spiperone label equivalent numbers of D2 and D3 dopamine receptors in a range of tissues and under different conditions.
abstract: [3H]Nemonapride and [3H]spiperone are very widely used to study dopaminergic systems in vitro and in vivo, but it has been reported that [3H]nemonapride and [3H]spiperone give markedly different Bmax values for preparations of D2 dopamine receptors from recombinant cell lines or animal tissues. We have used the two radioligands in parallel to study a range of dopamine receptors [D2(short), D2(long), and D3] in different buffers. Bmax values derived using either radioligand differ by an average of < 20%, independent of receptor type or buffer conditions. All competition experiments show that the two ligands compete at a single site. It seems that [3H]spiperone and [3H]nemonapride do not differentiate between different forms or populations of D2-like receptors.
authors: Research School of Biosciences, University of Kent, Canterbury, England, UK.
authors: J M
authors: JM
authors: Vile
authors: U M
authors: UM
authors: D'Souza
authors: P G
authors: PG
authors: Strange
mesh_terms: D000818:Animals; D001549:Benzamides / Q000378:metabolism*; D001665:Binding Sites; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D018492:Dopamine Antagonists / Q000378:metabolism; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D011995:Recombination, Genetic; D013134:Spiperone / Q000378:metabolism*; D014316:Tritium
chemical_list: D001549:Benzamides; D018492:Dopamine Antagonists; C493595:Drd3 protein, rat; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D014316:Tritium; D013134:Spiperone; C030265:nemonapride