title: Exposure to hypobaric hypoxia results in higher oxidative stress compared to normobaric hypoxia.
abstract: Sixteen healthy exercise trained participants underwent the following three, 10-h exposures in a randomized manner: (1) Hypobaric hypoxia (HH; 3450m terrestrial altitude) (2) Normobaric hypoxia (NH; 3450m simulated altitude) and (3) Normobaric normoxia (NN). Plasma oxidative stress (malondialdehyde, MDA; advanced oxidation protein products, AOPP) and antioxidant markers (superoxide dismutase, SOD; glutathione peroxidase, GPX; catalase; ferric reducing antioxidant power, FRAP) were measured before and after each exposure. MDA was significantly higher after HH compared to NN condition (+24%). SOD and GPX activities were increased (vs. before; +29% and +54%) while FRAP was decreased (vs. before; -34%) only after 10h of HH. AOPP significantly increased after 10h for NH (vs. before; +83%), and HH (vs. before; +99%) whereas it remained stable in NN. These results provide evidence that prooxidant/antioxidant balance was impaired to a greater degree following acute exposure to terrestrial (HH) vs. simulated altitude (NH) and that the chamber confinement (NN) did likely not explain these differences.
authors.affiliation: CRIS, University Claude Bernard Lyon 1, University of Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: Ribon
authors.affiliation: CRIS, University Claude Bernard Lyon 1, University of Lyon, France; Institut Universitaire de France, France.
authors.forename: V
authors.initials: V
authors.lastname: Pialoux
authors.affiliation: ISSUL, Institute of Sport Sciences, Department of Physiology, University of Lausanne, Switzerland.
authors.forename: J J
authors.initials: JJ
authors.lastname: Saugy
authors.affiliation: Laboratory of Exercise Physiology, University Savoie Mont-Blanc, Le Bourget-du-Lac, France.
authors.forename: T
authors.initials: T
authors.lastname: Rupp
authors.affiliation: ISSUL, Institute of Sport Sciences, Department of Physiology, University of Lausanne, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Faiss
authors.affiliation: Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: T
authors.initials: T
authors.lastname: Debevec
authors.affiliation: ISSUL, Institute of Sport Sciences, Department of Physiology, University of Lausanne, Switzerland. Electronic address: gregoire.millet@unil.ch.
authors.forename: G P
authors.initials: GP
authors.lastname: Millet
mesh_terms: D000328:Adult; D000531:Altitude; D001274:Atmospheric Pressure; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D010088:Oxidoreductases / Q000097:blood*
chemical_list: D010088:Oxidoreductases
keywords: Altitude; Antioxidant enzymes; Barometric pressure; Lipid peroxidation