Increased platelet membrane [3H]-LSD binding in patients on chronic neuroleptic treatment.
Using a [3H]-lysergic acid diethylamide [( 3H]-LSD) binding technique, platelet 5-hydroxytryptamine (5-HT) receptor number and affinity were compared in schizophrenics treated with depot thioxanthenes and phenothiazines and controls. There was an approximately 30% increase in platelet receptor number (Bmax) in the patient group. There was a decrease in affinity (increase in Kd) of about 30% in the patient group. This was probably due to the persistence of the neuroleptic in the platelet membrane preparation. There was a weak positive correlation between receptor number and total neuroleptic dosage. The increased number of 5-HT receptors is consistent with the previously reported enhancement of 5-HT-induced platelet aggregation in patients treated with long-term phenothiazines and thioxanthenes. Our findings are compatible with 5-HT up-regulation in human platelets produced by depot neuroleptic therapy. It is not known whether parallel changes may be occurring in brain 5-HT receptors.
Schächter
M
M
Geaney
D P
DP
Grahame-Smith
D G
DG
Cowen
P J
PJ
Elliott
J M
JM
D000328:Adult; D000375:Aging; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008238:Lysergic Acid Diethylamide / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011985:Receptors, Serotonin / Q000378:metabolism; D012559:Schizophrenia / Q000097:blood; D012737:Sex Factors; D013997:Time Factors
D014150:Antipsychotic Agents; D011985:Receptors, Serotonin; D008238:Lysergic Acid Diethylamide