Increase in nitric oxide levels and mitochondrial membrane potential in platelets of untreated patients with major depression.

Alterations in platelet activity have been associated with the onset of major depressive disorder (MDD) and with ischemic cardiovascular events through mechanisms that remain unknown. The present study evaluated nitric oxide (NO) levels, mitochondrial membrane potential (PMMP), and P-selectin expression in platelets from 30 untreated MDD patients and 30 matched controls by flow cytometry. In addition, tryptophan and serotonin concentrations were measured in the whole blood by high performance liquid chromatography.