Mianserin-induced up-regulation of serotonin receptors on normal human platelets in vivo.
The antidepressant, mianserin, is a serotonin receptor (5-HT2) antagonist and produces down-regulation of 5-HT2 and 5-HT1c receptors in the cerebral cortex of rats. In preparation for testing the validity of platelets as a model system for changes in 5-HT2 receptors during antidepressant drug treatment, mianserin (40 mg daily), was given to five human volunteers for five days, and platelets were collected on days 0, 1, 6, and 8. 5-HT2 receptor affinity and density were measured by specific binding of 125I-LSD, with and without an excess of spiperone. 5-HT uptake site affinity and density were determined by 3H-paroxetine binding, with and without an excess of fluoxetine. Platelet serotonin content was measured using high pressure liquid chromatography and electrochemical detention. Platelet 5-HT2 receptor density was increased and the ligand affinity was decreased during mianserin administration. In contrast, platelet 5-HT content was not altered significantly by mianserin administration, nor was platelet uptake site density and ligand affinity.
Whiteford
H A
HA
Clinical Studies Unit, Wolston Park Hospital, Wacol, Australia.
Jarvis
M R
MR
Stedman
T J
TJ
Pond
S
S
Csernansky
J G
JG
D000704:Analysis of Variance; D001792:Blood Platelets / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008803:Mianserin / Q000494:pharmacology*; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000378:metabolism; D012016:Reference Values; D015854:Up-Regulation / Q000187:drug effects
D011985:Receptors, Serotonin; D008803:Mianserin