Reactive Oxygen Species and the Cardiovascular System
Figure 1
Summary of production and removal of various reactive oxygen species. Superoxide () can dismutate in several ways, either spontaneously through a reaction with superoxide dismutase (SOD), through the Haber-Weiss reaction, or in reaction with nitric oxide (NO) and its radical (NO•). Through SOD, hydrogen peroxide (H2O2) is formed and further reduced by catalase and peroxidase to form water and oxygen. Also, H2O2 can be formed directly from xanthine oxidase. The hydroxyl radical (OH•) is formed through the Haber-Weiss reaction, through the Fenton reaction, and from peroxynitrous acid (HOONO). can also scavenge NO to form peroxynitrite (ONOO−) leading to nitroso-redox imbalance. NADH/NADPH oxidase: nicotinamide adenine dinucleotide (phosphate); (e)NOS: (endothelial) derived nitric oxide synthetase; NO: nitric oxide, NO2: nitric dioxide; mitoch. Oxidat. phosphor, mitochondrial oxidative phosphorylation; dotted lines: inhibition.
