**6.1 Free radical cause peroxynitrites**

Ischemia-reperfusion injury showed decreased levels of 3-nitrotyrosine-protein adducts. The iNOS-generated NO mediates damage in I-R injury possibly through ONOO▬ formation [103]. Patients with chronic renal failure (CRF) showed decreased endothelium-dependent vasodilatation to acetylcholine, have increased markers of oxidative stress, and diminished antioxidant activity [104]. ONOO▬ could induce entire mitochondrial protein nitration, responsible for the damage of renal mitochondria in diabetes [105]. Nitrosative stress is involved in cisplatininduced nephrotoxicity in rats through peroxynitrite-induced nephrotoxicity and protein nitration [106]. Renal hypoxia and ischemia promotes the formation of reactive oxygen species (ROS) such as superoxide radical anions, peroxides, and hydroxyl radicals, that can oxidatively damage biomolecules and membranes, and affect organelle function and induce renal tubule cell injury, inflammation, and vascular dysfunction [107].
