Nephrotoxicity of nickel nano and microparticles in rat- a comparative, time dependent study with special reference to antioxidant defence system

A comparative and time dependent study on the effects of nickel oxide nano and nickel oxide microparticles (5 mg/kg body weight) each, has been performed in the kidney of male Wistar rats at two intervals of 15 and 30 days. Morphological, functional changes and effects on antioxidant enzymes in the kidney were studied. Exposure to both, NiONPs and NiOMPs significantly enhanced the generation of reactive oxygen species viz. malondialdehyde, hydrogen peroxide and nitric oxide in rat kidney. However, increase was higher in NiONPs treated rats than NiOMPs treated rats. Diminished values for reduced glutathione and enzymes, that is, superoxide dismutase, glutathione peroxidise and catalase confirmed the role of oxidative stress in NiONPs induced nephrotoxicity. Increased oxidative DNA damage and histopathological changes further supported this hypothesis. Present results suggest that nanoparticles of nickel are more toxic to kidney than nickel metal ions. Reactive oxygen species are a critical factor in NiONPs induced renal toxicity in rat.