Effect of melatonin on active transport of serotonin into blood platelets.

Previous research has demonstrated that the circadian rhythm of melatonin negatively correlates with that of the sensitivity of platelet serotonin uptake sites. Moreover, serotonin has been found to be a competitive inhibitor of melatonin binding to platelets. The goal of the present study was to investigate whether melatonin directly affects platelet serotonin transport.

Kinetic values of active serotonin transport by platelets of bipolar, unipolar and schizophrenic patients at 2 and at 8 a.m. Preliminary report.

Serotonin active transport by platelets of psychiatric patients was determined at 2 and at 8 a.m. Kinetic values, Vmax and Km, of serotonin uptake by platelets of bipolar depressive patients at 2 a.

Phorbol-myristate-acetate-induced platelet aggregation in the presence of inhibitors.

4 beta-Phorbol-12-myristate-13-acetate (PMA) at 100 ng/ml was able to induce platelet aggregation in the presence of agents which inhibited aggregation, triggered by other agonists such as adenosine diphosphate sodium salt (ADP), thrombin and collagen. PMA induced aggregation in acid-citrate-dextrose platelet-rich plasma. 100 microM tetracaine, 5 microM bromophenacyl bromide and 0.