IntroductIon Nitric oxide (NO), released from the endothelial cells, is a potent vasodilating agent with antiatherogenic properties. 1 Several protective properties of NO in the vasculature are linked, among others, to the inhibition of platelet adhesion and aggregation, ability to lower the expression of endothelial surface adhesion molecules, lowering adhesion and infiltration of inflammatory cells into the endothelium, and reducing oxidative stress. NO may also contribute to regeneration of damaged endothelium, since it can mobilize the release of endothelial progenitor