Figure 1.

Generation of reactive species in diabetes. Highlighted in gray are some of the most important ROS and RNS in vascular cells. Oxygen is converted to ^•O₂^- via the activation of enzymatic and nonenzymatic pathways, which is then dismutated to H₂O₂ by SOD. H₂O₂ can be converted to H₂O by catalase or glutathione peroxidase (GSH-Px) or to ^•OH after reaction with Cu or Fe. Glutathione reductase regenerates glutathione (GSH). In addition, ^•O₂^- reacts rapidly with ^•NO to form ONOO^-.