title: Oxidative stress as a mechanism for toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D): studies with goldfish gills.
abstract: The effects of exposure to the widely used herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), at environmentally permitted (1 mg L(-1)), slightly toxic (10 mg L(-1)), and highly toxic (100 mg L(-1)) concentrations were analyzed in gills of goldfish, Carassius auratus, a popular fish model for ecotoxicological research. Fish were exposed to the pesticide in water for 96 h and an additional group of fish were treated by the highest 2,4-D concentration and then allowed to recover for further 96 h. Among markers of oxidative stress, goldfish exposure to 2,4-D did not affect carbonyl protein levels in the gills, but fish exposure to 100 mg L(-1) of 2,4-D enhanced lipid peroxide concentrations (by 58 %) and oxidized glutathione levels (by 49 %), the latter also significantly increasing (by 33 %) oxidized/total glutathione ratio. Activities of three enzymes of antioxidant defence also increased under 2,4-D exposure: superoxide dismutase (by 29-35 %), catalase (by 41 %), and glutathione peroxidase (by 19-33 %). Activities of other antioxidant associated enzymes as well as other potential markers of stress (e.g. aminotransferase enzymes, acetylcholinesterase, lactate metabolism) showed little or no response in gills to 2,4-D exposure. However, virtually all affected parameters returned to control values during recovery period. A combination of selected indices of oxidative stress and antioxidant defence, measured in fish gills, may provide to be effective biomarkers to assess environmental hazards of 2,4-D to freshwater ecosystems.
authors.affiliation: Department of Biochemistry and Biotechnology, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str, Ivano-Frankivsk, 76025, Ukraine.
authors.forename: Tetiana M
authors.initials: TM
authors.lastname: Atamaniuk
authors.forename: Olga I
authors.initials: OI
authors.lastname: Kubrak
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Storey
authors.forename: Volodymyr I
authors.initials: VI
authors.lastname: Lushchak
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D005880:Gills / Q000187:drug effects* / Q000201:enzymology; D006054:Goldfish / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D013997:Time Factors; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D014874:Water Pollutants, Chemical; D015084:2,4-Dichlorophenoxyacetic Acid