Serotonin levels in hypertension.

The present study examines the putative role of serotonin (5-hydroxytryptamine) in the pathogenesis of essential hypertension. Intraplatelet and plasma free serotonin levels, as well as the amounts released from aggregating platelets, were measured in six patients with untreated essential hypertension, using high performance liquid chromatography with electrochemical detection. Platelet serotonin contents were similar to those in age-matched controls. However, hypertensive patients showed significantly higher levels of plasma free serotonin as well as a significantly higher release from aggregating platelets, stimulated by collagen or adenosine diphosphate (ADP). These data suggest that serotonin may be involved in the pathogenesis of essential hypertension.