Schizophrenia: elevation of dopamine D4-like sites, using [3H]nemonapride and [125I]epidepride.
We here report a three-fold elevation of dopamine D4-like sites in schizophrenia, using [3H]nemonapride to measure dopamine D2 and D3 receptors and D4-like sites, and using [125I]epidepride to measure D2 and D3 sites in ten control and nine schizophrenia post-mortem brain putamen tissues. This result differs from a recent report which did not detect significant D4-like sites in control or schizophrenia putamen (Reynolds and Mason, 1995, Eur. J. Pharmacol. 281, R5). The present finding agrees with other reports wherein an elevation in D4-like sites was found in schizophrenia, using [3H]nemonapride for D2, D3 and D4-like sites, but [3H]raclopride for D2 and D3 sites. The nature of these D4-like sites is not known.
Seeman
P
P
Department of Pharmacology, University of Toronto, Canada.
Guan
H C
HC
Van Tol
H H
HH
D000368:Aged; D001549:Benzamides / Q000378:metabolism*; D003342:Corpus Striatum / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011759:Pyrrolidines / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000032:analysis*; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D012559:Schizophrenia / Q000378:metabolism*
D001549:Benzamides; C493593:DRD3 protein, human; C493599:DRD4 protein, human; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; C063525:epidepride; D050638:Receptors, Dopamine D4; C030265:nemonapride