title: Nickel induces hyperglycemia and glycogenolysis and affects the antioxidant system in liver and white muscle of goldfish Carassius auratus L.
abstract: The toxicity of nickel to mammals is well studied, whereas information on nickel effects on fish is scant. Goldfish exposure to 10-50 mg L(-1) of waterborne Ni(2+) for 96 h showed reduced glycogen levels by 27-33% and 37-40% in liver and white muscle, respectively, accompanied by substantial increases in blood glucose levels (by 15-99%). However, indices of oxidative damage to proteins (carbonyl proteins) and lipids (lipid peroxides) were largely unaffected by nickel exposure. In liver, the activities of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GPx), were not affected by Ni(2+) treatment, while catalase activity was elevated by 26%. In white muscle, however, substantial increases in SOD (by 38-147%) and GPx (by 2.5-5.5-fold) activities appeared to compensate for decreased catalase activity (by 59-69%) in order to resist Ni-induced oxidative perturbations. Both hepatic and muscular glutathione reductase activities were suppressed by 10-30% and 12-21%, respectively, after goldfish exposure to all Ni(2+) concentrations used. However, the activity of glucose-6-phosphate dehydrogenase was remarkably enhanced (by 1.6-5.4-fold) in white muscle of Ni-exposed fish, indicating a strong potential increase in NADPH production under Ni exposure. Thus, the exposure of goldfish to 10-50 mg L(-1) of Ni(2+) for 96 h induces glycogenolysis and hyperglycemia, showing some similarities with a hypoxia response, and leads to a substantial activation of defense systems against reactive oxygen species in liver and white muscle in tissue-specific and concentration-dependent manner.
authors.affiliation: Department of Biochemistry and Biotechnology, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk 76025, Ukraine.
authors.forename: Olga I
authors.initials: OI
authors.lastname: Kubrak
authors.forename: Bohdana M
authors.initials: BM
authors.lastname: Rovenko
authors.forename: Viktor V
authors.initials: VV
authors.lastname: Husak
authors.forename: Janet M
authors.initials: JM
authors.lastname: Storey
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Storey
authors.forename: Volodymyr I
authors.initials: VI
authors.lastname: Lushchak
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D005393:Fish Diseases / Q000139:chemically induced / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D050261:Glycogenolysis / Q000187:drug effects; D006054:Goldfish; D006943:Hyperglycemia / Q000139:chemically induced / Q000378:metabolism / Q000662:veterinary*; D007668:Kidney / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D009132:Muscles / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D009532:Nickel / Q000633:toxicity*; D018384:Oxidative Stress / Q000502:physiology; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008054:Lipid Peroxides; D014874:Water Pollutants, Chemical; D009532:Nickel; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase