Comparison of lymphocyte
versus platelet uptake of IDT307 in mixed
blood cell populations by flow cytometry. Peripheral blood cell samples
isolated from humans or rhesus monkeys containing both platelets and
lymphocytes were analyzed for IDT307 uptake by flow cytometry. (A)
SERT-specific function is not detectable in human lymphocytes using
the SERT inhibitors paroxetine (PRX; 100 nM), S-CIT (100 nM), clomipramine
(CMI; 100 nM), or 5-HT (500 μM). A high concentration of imipramine
(IMI; 100 μM) caused a modest decrease in IDT307 uptake in human
lymphocytes. (B) By contrast, human platelet SERT function is almost
completely abolished in the presence of the same concentrations of
inhibitors used in human lymphocytes. (C) IDT307-associated fluorescence
(green bar) in rhesus lymphocytes is not inhibited by different concentrations
of S-citalopram (S-CIT) or serotonin (5-HT; 500 μM). (D) Similar
to human platelets, rhesus platelet IDT307 uptake is significantly
inhibited by S-CIT or 5-HT. **P < 0.01 and ***P < 0.001 versus control. N = 3–6
samples per condition.