Red blood cells in the metabolism of nitric oxide-derived peroxynitrite

In this review we have analyzed the reactions of nitric oxide ((NO)-N-center dot) with superoxide radical (O-2(center dot-)) at the vascular compartment which results in limitation of the bioavailability of (NO)-N-center dot and the formation of peroxynitrite (ONOO-), a strong oxidant species. The intravascular formation of peroxynitrite can result in oxidative modifications of plasma and vessel wall proteins including the formation of protein-3-nitrotyrosine. The role of red blood cells (RBC) and oxyhemoglobin in the metabolism of intravascular peroxynitrite will be discussed. While RBC constitute an important 'sink' of both (NO)-N-center dot and peroxynitrite, redox reactions of these species with oxyhemoglobin may in part contribute to erythrocyte aging. The intravascular formation, reactions and detoxification of peroxynitrite are revealed as important factors controlling vascular dysfunction and degeneration in a variety of pathophysiologically-relevant conditions.