Nitric oxide is a highly versatile heterodiatomic molecule that effects a variety of actions in
the vasculture. Originally identified as a principal determination of vascular tone, nitric oxide
has since been recognized to exert anti thrombotic, antiproliferative, and anti-inflammatory
effects in the vasculture. At higher concentrations and in the setting of other oxidants, nitric
oxide can promote vascular pathology. In this review, we summarize the molecular
mechanisms of nitric oxides actions in vascular biology and pathology.