Changes in platelet 3-H-imipramine binding: influences of protein concentration of varying proportions of cytosol or intact platelets and displacing agents used.
Platelet 3-H-imipramine binding exhibits considerable variation, both interindividually and between several groups. The aim of this study was to measure 3-H-imipramine binding, simultaneously in platelet membranes vs. intact platelets vs. cytosol or intracytosolic protein in order to determine their effect on Bmax and Kd values. 3-H-imipramine binding was carried out at different protein concentrations. Our results indicate that the affinity constant is heavily influenced by the presence of cytosol and intact platelets in membrane preparations. Finally, we demonstrate a negative correlation between Bmax and protein concentration. Only perfect analytical conditions will allow platelet 3-H-imipramine binding to be a biological marker for affective disorders.
Rosel-Soria
P
P
Hormone Unit, Hospital Princeps d'Espanya, Barcelona, Spain.
Vallejo
J
J
Oros
M
M
Serrallonga
J
J
Menchon
J M
JM
Navarro
M A
MA
D001667:Binding, Competitive; D001792:Blood Platelets / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism*; D006801:Humans; D007099:Imipramine / Q000493:pharmacokinetics; D011869:Radioligand Assay; D011955:Receptors, Drug / Q000378:metabolism*
D001798:Blood Proteins; D002352:Carrier Proteins; D011955:Receptors, Drug; C027775:imipramine receptor; D007099:Imipramine