Increased [3H] raclopride binding sites in postmortem brains from schizophrenic violent suicide victims.
The specific binding of the D2-dopamine receptor antagonist radioligand [3H] raclopride was quantitated in the postmortem caudate and frontal cortex from schizophrenic suicide victims and control subjects. In schizophrenic suicides the density of binding sites (Bmax) was higher (40%, P < 0.05) in the caudate, whereas it did not change in the cortex as compared to those in controls. The apparent dissociation constants (KD) were also found increased both in caudate (24%) and cortex (75%) from schizophrenics, but these apparent decreases in receptor affinity did not reach statistical significance. The mean Bmax value in drug-free schizophrenic suicides (n = 3) did not differ from the Bmax value in neuroleptic drug-treated schizophrenics (n = 7) but it was found increased in respect to control subjects (n = 9). No differences in [3H] raclopride binding were observed between non-schizophrenic suicide victims (n = 4) and matched controls (n = 4), suggesting that the modifications of D2-dopamine receptors in schizophrenia are not related to suicide.
Ruiz
J
J
Department of Pharmacology, University of the Basque Country, Leioa, Bizkaia.
Gabilondo
A M
AM
Meana
J J
JJ
García-Sevilla
J A
JA
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001923:Brain Chemistry / Q000502:physiology*; D002421:Caudate Nucleus / Q000378:metabolism; D018492:Dopamine Antagonists / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008566:Membranes / Q000378:metabolism; D008875:Middle Aged; D011180:Postmortem Changes; D017397:Prefrontal Cortex / Q000378:metabolism; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D012457:Salicylamides / Q000378:metabolism*; D012559:Schizophrenia / Q000188:drug therapy / Q000378:metabolism*; D013405:Suicide
D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D012457:Salicylamides; D020891:Raclopride