Diurnal concordance of human platelet serotonin content and plasma alpha-1-acid glycoprotein concentration.
The diurnal rhythm of platelet serotonin (5-HT) content and plasma alpha-1-acid glycoprotein (AGP) was investigated in twelve healthy male volunteers aged 19-30 years. Platelet 5-HT content and plasma AGP concentration varied across a twenty-four hour sampling period in a manner consistent with a circadian pattern. Platelet 5-HT levels rose from baseline at 5.00 hr to a peak at 14.00 hr and slowly declined to baseline during the night-time hours. A concordant pattern was observed for plasma AGP with peak concentrations occurring between 8.00 hr and 14.00 hr. These findings support the notion that AGP is a positive endogenous allosteric stimulator of platelet 5-HT transport, since there is a direct relationship between platelet 5-HT levels and plasma AGP concentration. A theoretical model is presented to explain the diurnal effects of AGP on the platelet 5-HT transporter.
Meyerson
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LR
Medical Research Division of American Cyanamid Company, Ramapo College, Mahwah, NJ 07430.
Strano
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R
Ocheret
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D000328:Adult; D001792:Blood Platelets / Q000032:analysis*; D002940:Circadian Rhythm; D006801:Humans; D008297:Male; D008954:Models, Biological; D009961:Orosomucoid / Q000032:analysis* / Q000502:physiology; D012701:Serotonin / Q000032:analysis*
D009961:Orosomucoid; D012701:Serotonin