DIFFERENTIAL-EFFECTS OF LITHIUM ON PLATELET PROTEIN-PHOSPHORYLATION IN BIPOLAR PATIENTS AND HEALTHY-SUBJECTS

In the present study we have investigated the cAMP-dependent phosphory lation system in platelets of euthymic bipolar patients and healthy vo lunteers before and after 15 days of lithium treatment. The results sh owed that 15 days of lithium treatment enhanced the basal and the cAMP -stimulated P-32 incorporation in the 22 and 38 kDa phosphoproteins in bipolar patients, but not in healthy subjects. Moreover, we provided further evidence of increased phosphorylation in the 22 kDa platelet p hosphoprotein in untreated euthymic bipolar patients when compared wit h controls. Overall, these findings suggest an implication of protein phosphorylation in the biochemical action of lithium and in the pathop hysiology of bipolar disorder.