title: Antioxidative defense and oxidative stress in ringed seals (Pusa hispida) from differently polluted areas.
abstract: High contaminant levels detected in Baltic seals have been associated with various health effects. In this study several parameters related to antioxidative defense and oxidative stress (concentrations of reduced and oxidised glutathione, lipid hydroperoxide and vitamin E, activities of glutathione reductase, peroxidase and S-transferase, glucose-6-phosphate dehydrogenase, catalase, and superoxidedismutase) were measured in the livers of ringed seals from the Baltic Sea and from a less contaminated reference area, Svalbard, Norway. Seals were caught during two different time periods 1996-1997 and 2002-2007, which represent different levels of contamination. No signs of oxidative damage were found in the Baltic seals. However, glutathione metabolism was enhanced in the ringed seals from the Baltic Sea compared to the seals from Svalbard. The adaptation to dive where repetitive ischemia/reperfusion occurs naturally may contribute to the resistance of oxidative stress and to the capacity to increase enzymatic antioxidant defense in phocid seals. This could explain the similarities in oxidative stress levels despite the differences in antioxidant responses between the ringed seals from the Baltic Sea and Svalbard.
authors.affiliation: Division of Genetics and Physiology, Department of Biology, University of Turku, FI-20014 Turku, Finland. mmkane@utu.fi
authors.forename: Mirella
authors.initials: M
authors.lastname: Kanerva
authors.forename: Heli
authors.initials: H
authors.lastname: Routti
authors.forename: Yael
authors.initials: Y
authors.lastname: Tamuz
authors.forename: Madeleine
authors.initials: M
authors.lastname: Nyman
authors.forename: Mikko
authors.initials: M
authors.lastname: Nikinmaa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D017753:Ecosystem; D005978:Glutathione / Q000097:blood / Q000378:metabolism; D019803:Glutathione Disulfide / Q000097:blood / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000201:enzymology; D009792:Oceans and Seas; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species; D046048:Seals, Earless; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione; D019803:Glutathione Disulfide