title: Changes in arterial PO₂, physiological blood parameters and intracellular antioxidants in free-swimming Atlantic cod (Gadus morhua) exposed to varying levels of hyperoxia.
abstract: Free-swimming Atlantic cod (Gadus morhua) were exposed to water oxygen pressures (P(w)O₂) ranging from 18.1 to 41.5 kPa and sampled for blood using an indwelling caudal artery cannula. Arterial blood oxygen pressure (P(a)O₂) increased with increasing P(w)O₂, from 12.0 kPa in normoxia (18.1 kPa) to 34.2 kPa in the highest hyperoxic level tested (41.5 kPa). Blood CO₂ pressure and plasma bicarbonate concentration increased with P(w)O₂, indicating reduced ventilation with increased P(w)O₂. Plasma glucose, sodium and potassium were not affected by water oxygen level. Blood oxidative stress biomarkers, reduced glutathione, oxidized glutathione and the oxidative stress index (ratio between oxidized and total glutathione) differed intermittently between normoxia and hyperoxia. The oxidative stress index was higher in the blood of exposed compared to unexposed control cod. Together with elevated P(a)O₂, these findings suggest increased production of reactive oxygen species and increased oxidative stress in Atlantic cod exposed to hyperoxia.
authors.affiliation: Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, Ås, Norway. anders.karlsson@umb.no
authors.forename: Anders
authors.initials: A
authors.lastname: Karlsson
authors.forename: Lene Sørlie
authors.initials: LS
authors.lastname: Heier
authors.forename: Bjørn Olav
authors.initials: BO
authors.lastname: Rosseland
authors.forename: Brit
authors.initials: B
authors.lastname: Salbu
authors.forename: Anders
authors.initials: A
authors.lastname: Kiessling
mesh_terms: D000136:Acid-Base Equilibrium / Q000502:physiology; D000332:Aerobiosis / Q000502:physiology; D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D001158:Arteries / Q000502:physiology*; D001639:Bicarbonates / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002245:Carbon Dioxide / Q000097:blood; D048389:Gadus morhua / Q000097:blood* / Q000502:physiology*; D042541:Intracellular Space / Q000378:metabolism / Q000502:physiology*; D007477:Ions / Q000097:blood; D018384:Oxidative Stress / Q000502:physiology; D010100:Oxygen / Q000097:blood* / Q000378:metabolism; D011188:Potassium / Q000097:blood; D017382:Reactive Oxygen Species / Q000378:metabolism; D012964:Sodium / Q000097:blood
chemical_list: D000975:Antioxidants; D001639:Bicarbonates; D015415:Biomarkers; D001786:Blood Glucose; D007477:Ions; D017382:Reactive Oxygen Species; D002245:Carbon Dioxide; D012964:Sodium; D011188:Potassium; D010100:Oxygen