[3H]raclopride binding to brain tissue from subjects with schizophrenia: methodological aspects.
The binding of [3H]raclopride to particulate membrane and frozen sections (with quantitative autoradiography) from the caudate-putamen, obtained at autopsy from schizophrenic and non-schizophrenic subjects, was measured. The affinity of [3H]raclopride to particulate membrane was significantly decreased in the schizophrenic compared to non-schizophrenic subjects. The density of [3H]raclopride binding to tissue from subjects with schizophrenia was increased, unchanged or decreased depending on the methodology used. Finally, there was an age-dependent decrease in [3H]raclopride binding in the frozen sections from the caudate-putamen of the non-schizophrenic subjects. This age-dependent decrease was not apparent using particulate membrane from schizophrenic or non-schizophrenic subjects or tissue sections from the schizophrenic subjects. We conclude that the binding of [3H]raclopride is dependent on methodology and therefore data from in vitro and in vivo studies using this drug should be interpreted with caution.
Dean
B
B
Rebecca L. Cooper Research Laboratories, Mental Health Research Institute of Victoria, Parkville, Australia. bdean@papyrus.mhri.edu.au
Pavey
G
G
Opeskin
K
K
D000328:Adult; D000368:Aged; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D002421:Caudate Nucleus / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D018492:Dopamine Antagonists / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D011485:Protein Binding; D011699:Putamen / Q000378:metabolism; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000378:metabolism; D012457:Salicylamides / Q000378:metabolism*; D012559:Schizophrenia / Q000378:metabolism*
D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D012457:Salicylamides; D020891:Raclopride