"Endothelium and vasomotor tone"

     The vascular endothelium plays an important role in the control of the circulation. It metabolizes various vasoactive substances, converts angiotensin I to angiotensin II and secretes the potent vasodilators like prostacyclin and nitric oxide, as well as vasoconstrictors like endothelin-1. The balance between these mediators determines vascular tone, and as a consequence, several different physiological and pathophysiological states of the cardiovascular system.