Platelet [H-3]imipramine and [H-3]paroxetine binding in depressed patients

[H-3]Paroxetine and [H-3]imipramine binding to blood platelet membranes was simultaneously measured in 63 control subjects and 18 patients with DSM-III-R criteria for major depression with melancholia. Both binding sites showed significantly different (p < 0.001) maximum binding (B-max) and equilibrium dissociation constant (K-d) values. Age was not correlated with either [H-3]imipramine B-max or K-d values, but a negative correlation was found between [H-3]paroxetine B-max and age in healthy controls. Furthermore, depressed patients showed significantly lower [H-3]imipramine B-max values (p < 0.001) and higher K-d values (p < 0.001) in comparison to the control group. No differences were observed in [H-3]paroxetine B-max and K-d values between the two groups. (C) 1997 Elsevier Science B.V.