Comparative study of platelet 3H-paroxetine and 3H-imipramine binding in panic disorder patients and healthy controls.

High affinity 3H-paroxetine and 3H-imipramine binding sites were simultaneously studied in platelets of 29 untreated patients with panic disorder and 12 healthy controls. The maximum number of binding sites (Bmax) was found to be significantly lower in the panic patients compared to the controls using either ligand. No difference in the Kd values between the groups of subjects was found. The disturbance of serotonin neurotransmission in panic disorder--decrease in Bmax values--may be either a consequence or a reason of serotonergic dysfunction.