SCHIZOPHRENIA - ELEVATION OF DOPAMINE D-4-LIKE SITES, USING [H-3] NEMONAPRIDE AND [I-125]EPIDEPRIDE

We here report a three-fold elevation of dopamine D-4-like sites in schizophrenia, using [H-3]nemonapride to measure dopamine D-2 and D-3 receptors and D-4-like sites, and using [I-125]epidepride to measure D-2 and D-3 sites in ten control and nine schizophrenia post-mortem brain putamen tissues. This result differs from a recent report which did not detect significant D-4-like sites in control or schizophrenia putamen (Reynolds and Mason, 1995, fur. J. Pharmacol. 281, R5). The present finding agrees with other reports wherein an elevation in D-4-like sites was found in schizophrenia, using [H-3]nemonapride for D-2, D-3 and D-4-like sites, but [H-3]raclopride for D-2 and D-3 sites. The nature of these D-4-like sites is not known.