Lymphocytes of healthy subjects and schizophrenic patients possess no high-affinity binding sites for spiroperidol.
We investigated 3H- and 125I-spiroperidol binding to lymphocytes from healthy subjects and schizophrenic patients and compared it with that to a porcine striatum dopaminergic D2-receptor preparation using identical conditions. Incubation for 60 min at 37 degrees C reduced lymphocyte 3H-spiroperidol binding to 29% of its maximal value. Binding of 3H- and 125I-spiroperidol to striatal membranes was saturable and showed high affinity; the apparent half-maximal saturation constants, KD, were 0.5 nmol/l and 1.0 nmol/l respectively for the two ligands. Lymphocyte membranes did not possess high-affinity binding sites for 3H-spiroperidol; binding to intact lymphocytes was saturable in the micromolar range; the KD values of healthy subjects and schizophrenic patients were similar. Validating all lymphocyte binding studies by parallel experiments with a striatal receptor preparation showed that human lymphocytes do not possess physiologically relevant high-affinity spiroperidol receptors.
Rao
M L
ML
Universitätsnervenklinik, Psychiatrie, Bonn, FRG.
Deister
A
A
Roth
A
A
D000328:Adult; D002462:Cell Membrane / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011954:Receptors, Dopamine / Q000378:metabolism; D012559:Schizophrenia / Q000097:blood*; D013134:Spiperone / Q000097:blood*
D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D011954:Receptors, Dopamine; D013134:Spiperone