Homocysteine, EDRF, and endothelial function.

Nitric oxide, a heterodiatomic molecule, serves as an endothelium-dependent vasodilator and an antithrombotic agent in the vasculature. Because of its reactivity under physiological conditions, accumulating data suggest that nitric oxide forms adducts with several classes of biologic compounds, one of which is the sulfhydryl functionality, to form thionitrites or S-nitrosothiols. In this overview, we will examine the effects of S-nitrosothiols in the vascular system as modulators of tone and inhibitors of platelet activation to understand better what role these compounds may play in physiological and pathological states. With this background, we will review the role nitric oxide (EDRF) plays in helping to ameliorate vascular injury by homocysteine.