title: Antioxidant defenses and biochemical changes in pacu (Piaractus mesopotamicus) in response to single and combined copper and hypoxia exposure.
abstract: The effect of combined-factors (hypoxia+copper) on the biochemical parameters and antioxidant defenses were studied in the neotropical fish Piaractus mesopotamicus. Fish were exposed for 48 h to 0.4 mg Cu(2+) L(-1) (0.4Cu), hypoxia=50 mm Hg (Hpx), and 0.4 mg Cu(2) L(-1)+hypoxia=50 mm Hg (0.4CuHpx). The exposure to 0.4Cu increased the reactive oxygen species (ROS) in the liver, accompanied by increases in superoxide dismutase (SOD) and decreases in catalase (CAT) activity, showing the influence of copper in this protection. The exposure to Hpx decreased the activity of glutathione peroxidase (GSH-Px) and CAT. Exposure to a combined-factor caused an increase in the ROS production followed by an increase in SOD and a decrease in GSH-Px and CAT. At 0.4Cu, fish presented a reduction in CAT, while in Hpx decreases in SOD, CAT and GSH-Px were observed in red muscles. Single-factors were insufficient to cause ROS production. In combined-factors, increased ROS formation and decreased SOD, CAT and GSH-Px were observed. RBC increased in all groups, but only under combined-factors was there an increase in hemoglobin. Copper plasma concentration increased in groups exposed to copper. Na(+)/K(+)-ATPase activity in gills decreased in 0.4Cu and 0.4CuHpx, and increased in Hpx. Metallothionein concentration in gills increased under combined-factors. Combined-factors caused significant disturbances in the antioxidant defenses and biochemical parameters than single-factors.
authors.affiliation: Laboratory of Zoophysiology and Comparative Biochemistry, Department of Physiological Sciences, Federal University of São Carlos, São Carlos, SP, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Garcia Sampaio
authors.forename: Cheila
authors.initials: C
authors.lastname: de Lima Boijink
authors.forename: Eliane
authors.initials: E
authors.lastname: Tie Oba
authors.forename: Laila
authors.initials: L
authors.lastname: Romagueira Bichara dos Santos
authors.forename: Ana
authors.initials: A
authors.lastname: Lúcia Kalinin
authors.forename: Francisco
authors.initials: F
authors.lastname: Tadeu Rantin
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D019327:Copper Sulfate / Q000097:blood / Q000633:toxicity*; D004906:Erythrocyte Count; D029941:Fish Proteins / Q000378:metabolism; D005399:Fishes / Q000378:metabolism*; D005880:Gills / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D000860:Hypoxia / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008668:Metallothionein / Q000378:metabolism; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000097:blood / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D029941:Fish Proteins; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000254:Sodium-Potassium-Exchanging ATPase; D019327:Copper Sulfate