Pollution induced nitrative stress and heat shock protein 70 overexpression in fish liver mitochondria

• Published in: The Science of the total environment 2009-02, Vol.407 (4), p.1307-1317
• Main Authors: Padmini, E., Vijaya Geetha, B., Usha Rani, M.
• Format: Article
• Language: English
• Subjects: Adenosine Diphosphate - analysis; Adenosine Diphosphate - metabolism; Adenosine Triphosphate - analysis; Adenosine Triphosphate - metabolism; Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Blotting, Western; Chains; Damage; Ecosystem; Ecotoxicology, biological effects of pollution; Elevated; Energy status; Energy use; Environmental pollutants; Enzyme activity; Estuaries; Estuarine contamination; Fish; Fundamental and applied biological sciences. Psychology; General aspects; Glutathione; Glutathione - metabolism; Glutathione Disulfide - metabolism; Glutathione Peroxidase - metabolism; Health; Heat shock proteins; HSP70 Heat-Shock Proteins - metabolism; Liver; Liver - drug effects; Liver - metabolism; Marine; Mitochondria; Mitochondria, Liver - drug effects; Mitochondria, Liver - enzymology; Mitochondria, Liver - metabolism; Mitochondrial HSP70; Mugil cephalus; Nitric oxide; Nitric Oxide - metabolism; Peroxidase; Pollutants; Pollution; Respiratory chain enzymes; Smegmamorpha - metabolism; Stresses; Superoxide dismutase; Superoxide Dismutase - metabolism; Synthesis; Thiols; Tyrosine - analogs & derivatives; Tyrosine - blood; Tyrosine - metabolism; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity; Water pollution
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2008.09.038

Exposure to heavy metals and organic pollutants in natural water bodies can have detrimental effects on fish health. A combination of biochemical and energy studies were used to observe the changes in fish liver mitochondria in response to environmental pollutant induced nitrative stress in natural field conditions . The fish samples Mugil cephalus were collected from polluted (Ennore) and unpolluted (Kovalam) estuaries for a period of two years. The results revealed elevated nitrite (NO 2 −) and nitrate (NO 3 −) levels, increased nitric oxide (NO) synthesis and 3-nitrotyrosine expression, decreased respiratory chain enzyme activities and ATP/ADP ratio, reduced mitochondrial superoxide dismutase (MnSOD), glutathione peroxidase (Gpx) levels, diminished thiol status that leads to alterations in the mitochondrial function and elevated mitochondrial heat shock protein 70 (mtHSP70) expression (30%) to a significant extent in fish from the polluted estuary than in the unpolluted estuary. The overexpression of HSP70 under stress may aid mitochondrial survival by protecting against nitrative stress induced damage. The results also reveal the percentage increase in fish liver mitochondrial HSP70 in response to cumulative effect of environmental pollutants.