title: Biomarker responses in polar cod (Boreogadus saida) exposed to dietary crude oil.
abstract: Polar cod Boreogadus saida were exposed weekly to two doses of dietary crude oil for 4 weeks followed by 2 weeks of depuration. Administered doses corresponded on average to 4 and 9microgSigmaPAHsg(-1)fishweek(-1). Cytochrome P4501A1 (cyp1a1) and glutathione S-transferase (gst) mRNA expression, ethoxyresorufin O-deethylase (EROD) activity and metabolites in the bile showed strong and dose-dependent inductions at 2 and 4 weeks of exposure. Following 2 weeks depuration, mRNA expression of cyp1a1 and gst and PAH metabolites returned to basal levels while EROD activity and GST activity were still induced in the high oil treatment. The mRNA expressions of antioxidant defense genes (catalase, glutathione peroxidase and cytosolic and mitochondrial superoxide dismutase) did not change significantly during the experiment. Catalase activity was significantly depressed at week 2 in the high oil treatment. We conclude that the cyp1a1 mRNA expression, EROD activities and bile metabolites were the most reliable biomarkers of exposure while gst mRNA expression and GST activity were less sensitive and are considered only as complementary. Antioxidant defenses were poor biomarkers to assess effects of crude oil exposure in polar cod.
authors.affiliation: Akvaplan-niva, Polar Environmental Centre, Tromsø, Norway. jasmine.nahrgang@gmail.com
authors.forename: Jasmine
authors.initials: J
authors.lastname: Nahrgang
authors.forename: Lionel
authors.initials: L
authors.lastname: Camus
authors.forename: Patrice
authors.initials: P
authors.lastname: Gonzalez
authors.forename: Martina
authors.initials: M
authors.lastname: Jönsson
authors.forename: Jørgen S
authors.initials: JS
authors.lastname: Christiansen
authors.forename: Haakon
authors.initials: H
authors.lastname: Hop
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis* / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects*; D048388:Gadiformes / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005982:Glutathione Transferase / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010578:Petroleum / Q000633:toxicity*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase