Disruption of vascular signalling by the reaction of nitric oxide with superoxide: implications for cardiovascular disease.

Oxidation reactions are used in controlled enzymatic pathways to form intracellular messengers such as the prostaglandins, leukotrienes, and the simplest signalling molecule known, nitric oxide. In inflammation, non-enzymatic oxidation appears to produce compounds which compete with or inhibit the mediators derived from endogenous enzymatic oxidative processes. Many of these compounds could be derived from the reaction of NO with superoxide to form peroxynitrite and the ensuing oxidation, nitration and nitrosation reactions. In this short over-view we will describe some of these products and how they may modulate signal transduction events in the vasculature and so contribute to the pathogenesis of atherosclerosis.