[Vascular NAD(P)H oxidases--role in the pathogenesis of atherosclerosis]

Vascular NAD(P)H oxidases are multicomponent enzymes found in vascular smooth muscle cells and endothelial cells. Vascular NAD(P)H oxidases are predominant sources of superoxide in the vasculature. Active forms of NAD(P)H oxidases are associated with plasma membrane and consist of at least six components, namely: NOX, p22phox peptides and p47phox, p67phox, p40phox and Rac. Angiotensin II is the most important activator of NAD(P)H oxidases in vasculature. Angiotensin II induces superoxide and superoxide-derived hydrogen peroxide production, which may stimulate many proatherosclerotic processes, including increased expression of adhesion molecules, chemoattractants and activation of transcription factor NF-kappaB. Moreover, reactive oxygen species produced by NAD(P)H oxidases may be involved in endothelial cells apoptosis, oxidation of low density lipoproteins and vascular myocytes hypertrophy and proliferation. Specific inhibitors of NAD(P)H oxidases may be useful experimental tools for atherosclerosis research and may have potential therapeutic significance in the future.