Platelet alpha2-adrenoreceptors in obsessive-compulsive disorder

The need for new therapeutic targets in obsessive-compulsive disorder (OCD) prompted us to investigate the putative involvement of the norepinephrine system by means of platelet alpha(2)-adrenoreceptors in a group of 20 OCD patients and healthy control subjects, matched for sex and age. Platelet membranes were prepared according to standard protocols, and the alpha(2)-adrenoreceptors were measured by means of the specific binding of [(3)H]rauwolscine, a highly selective antagonist for this receptor subtype. The results, which showed no difference between patients and controls in the binding parameters of [(3)H]rauwolscine, suggest that the role of alpha(2)-adrenoreceptors, as reflected by the platelet model, is quite limited in OCD and may, perhaps, be restricted purely to some symptoms or dimensions such as motricity, as suggested by the higher density of alpha(2)-adrenoreceptors found in patients concomitantly affected by motor tics.