Human platelets possess multiple [3H]imipramine binding sites.
Scatchard analysis of [3H]imipramine binding to human platelets over the concentration range of 0.1-250 nM revealed a biphasic concave upward curve. Computer-assisted analysis indicated the best fit of the data by a two-site model with apparent Kd values of 0.68 and 293 nM and apparent Bmax values of 802 fmol/mg protein and 12.72 pmol/mg protein for the high- and low-affinity components, respectively. These results demonstrate the complex manner in which [3H]imipramine binding to human platelets, suggesting a reason for inconsistencies in Bmax values reported in the literature. Further studies of these low- as well as high-affinity sites may help elucidate the functional role of [3H]imipramine binding sites in affective disorders.
D001792:Blood Platelets / Q000032:analysis*; D002352:Carrier Proteins; D006801:Humans; D007099:Imipramine / Q000097:blood; D066298:In Vitro Techniques; D007700:Kinetics; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter / Q000032:analysis*; D014316:Tritium
D002352:Carrier Proteins; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter; C027775:imipramine receptor; D014316:Tritium; D007099:Imipramine