title: Goldfish exposure to cobalt enhances hemoglobin level and triggers tissue-specific elevation of antioxidant defenses in gills, heart and spleen.
abstract: Cobalt ions can enhance the generation of reactive oxygen species (ROS), which may be the reason for cobalt toxicity. This study aimed to determine whether Co(2+) toxicity in goldfish is related to induced oxidative stress in gills, heart and spleen, and to assess responses of antioxidant systems. Exposure of goldfish to 50, 100 and 150 mg L(-1) of Co(2+) for 96 h elevated total hemoglobin in blood by 23, 44 and 78%, respectively. In gills, cobalt exposure enhanced lipid peroxide levels and activities of primary antioxidant enzymes; superoxide dismutase (SOD) rose by 125% and glutathione peroxidase (GPx) increased by 53-296%. Glutathione-S-transferase (GST) activity also increased by 117-157% and glucose-6-phosphate dehydrogenase (G6PDH) enhanced by 46-96%. Heart showed limited effects of fish exposure to 50 or 100 mg L(-1) of Co(2+), but the exposure to 150 mg L(-1) of Co(2+) elevated concentrations of lipid peroxides by 123% and activities of GPx by 98% and SOD by 208%. The most substantial effects of goldfish exposure to Co(2+) were observed in spleen: a decrease in total protein concentration by 44-60% and high molecular mass thiols by 59-82%, reduced activities of catalase by 24-58% and GR by 25-68%, whereas the level of low molecular mass thiols increased by 153-279% and activities of GPx, GST, G6PDH were enhanced by 114-120%, 192-769%, and 256-581%, respectively. The data show that fish exposure to 50-150 mg L(-1) of Co(2+) elevates blood hemoglobin level, mimicking effects of hypoxia, and causes the activation of defense systems against ROS.
authors: Department of Biochemistry and Biotechnology, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine.
authors: Olga I
authors: OI
authors: Kubrak
authors: Bohdana M
authors: BM
authors: Rovenko
authors: Viktor V
authors: VV
authors: Husak
authors: Olena Yu
authors: OY
authors: Vasylkiv
authors: Kenneth B
authors: KB
authors: Storey
authors: Janet M
authors: JM
authors: Storey
authors: Volodymyr I
authors: VI
authors: Lushchak
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D003035:Cobalt / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D029941:Fish Proteins / Q000378:metabolism; D005880:Gills / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006054:Goldfish / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008054:Lipid Peroxides / Q000378:metabolism; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D013154:Spleen / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014131:Trace Elements / Q000633:toxicity
chemical_list: D000975:Antioxidants; D029941:Fish Proteins; D006454:Hemoglobins; D008054:Lipid Peroxides; D014131:Trace Elements; D003035:Cobalt; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase