The vascular endothelium has vasodilator, anti-thrombotic and athero-protective properties through the production of vasoactive mediators, such as nitric oxide (NO) and prostacyclin. NO is generated from the amino acid L-arginine by the enzyme NO synthase (NOS). Prostacyclin is produced from arachidonic acid by a series of enzymes including cyclo-oxygenase (COX) and prostaglandin polymerase.
