Oxidative stress in humans during and after 4 hours of hypoxia at a simulated altitude of 5500 m.

BACKGROUND High-altitude hypoxia may induce oxidative stress in humans. However, the effect of acute, severe, and non-acclimatized short-term hypobaric hypoxia exposure in humans has not been described. Additionally, little is known regarding the confounding role of reoxygenation in the extent of oxidative stress and damage markers in hypoxia. Our goals were to analyze the effect of of hypobaric hypoxia and reoxygenation on plasma oxidative stress and oxidative damage. METHODS There were six male volunteers exposed to a simulated altitude of 5500 m (52.52 kPa) in the INEFC-UB hypobaric chamber over 4 h and returned to sea level (SL) in 30 min. Data were collected at baseline SL at 1 h and 4 h of hypoxia at 5500 m and immediately after return to sea level (RSL). RESULTS Elevated scores of acute mountain sickness (13) and significant changes in arterial oxygen saturation (97.5 +/- 0.5; 53.3 +/- 1.9; 97.1 +/- 0.3%, p < 0.05 at SL, 4 h, and RSL, respectively) were observed. Significant reductions (p < 0.05) on total glutathione (TGSH) content were measured from SL and 1 h vs. 4 h and RSL. The percentage of oxidized glutathione (%GSSG) as an indicator of redox oxidative changes increased significantly (SL vs. 1 h; 1 h vs. 4 h, and RSL). Lipid peroxidation (TBARS), protein oxidation (SH protein groups), and total antioxidant status (TAS) followed the redox changes suggested by the glutathione system throughout the protocol. CONCLUSIONS Hypobaric hypoxia increased the burden of plasma oxidative stress and damage markers all through the hypoxia period. However, no additional changes were observed with reoxygenation at the end of the reoxygenation period.

[1]  H. Gerngross,et al.  Oxygen saturation course and altitude symptomatology during an expedition to broad peak (8047 m). , 2002, International journal of sports medicine.

[2]  M. Matsuda,et al.  Moderate physical exercise induces the oxidation of human blood protein thiols. , 2002, Life sciences.

[3]  S. Sharma,et al.  Antioxidant effect of beta-carotene on hypoxia induced oxidative stress in male albino rats. , 2002, Journal of ethnopharmacology.

[4]  I. Young,et al.  Intermittent hypoxic training: implications for lipid peroxidation induced by acute normoxic exercise in active men. , 2001, Clinical science.

[5]  P. Hackett,et al.  Frontiers of hypoxia research: acute mountain sickness. , 2001, The Journal of experimental biology.

[6]  P. Robach,et al.  Operation Everest III (Comex'97): the effect of simulated sever hypobaric hypoxia on lipid peroxidation and antioxidant defence systems in human blood at rest and after maximal exercise. , 2001, Resuscitation.

[7]  I. Young,et al.  A potential role for free radical-mediated skeletal muscle soreness in the pathophysiology of acute mountain sickness. , 2001, Aviation, space, and environmental medicine.

[8]  C. Lundby,et al.  Acute hypoxia and hypoxic exercise induce DNA strand breaks and oxidative DNA damage in humans , 2001, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[9]  N. Voelkel,et al.  Generation of oxidative stress contributes to the development of pulmonary hypertension induced by hypoxia. , 2001, Journal of applied physiology.

[10]  J A Neubauer,et al.  Physiological and Genomic Consequences of Intermittent Hypoxia Invited Review: Physiological and pathophysiological responses to intermittent hypoxia , 2001 .

[11]  E. Rimm,et al.  Gender differences in exercise-induced changes in sex hormone levels and lipid peroxidation in athletes participating in the Hawaii Ironman triathlon. Ginsburg-gender and exercise-induced lipid peroxidation. , 2001, Clinica chimica acta; international journal of clinical chemistry.

[12]  M. Serafini,et al.  Total antioxidant capacity as a tool to assess redox status: critical view and experimental data. , 2000, Free radical biology & medicine.

[13]  T. Skalak,et al.  Role of leukocytes and tissue-derived oxidants in short-term skeletal muscle ischemia-reperfusion injury. , 2000, American journal of physiology. Heart and circulatory physiology.

[14]  J. Richalet,et al.  An anxiety, personality and altitude symptomatology study during a 31-day period of hypoxia in a hypobaric chamber (experiment 'Everest-Comex 1997'). , 1999, Journal of environmental psychology.

[15]  J. Wood,et al.  Systemic hypoxia promotes leukocyte-endothelial adherence via reactive oxidant generation. , 1999, Journal of applied physiology.

[16]  D. Roberts,et al.  Effect of antioxidant supplementation on urine and blood markers of oxidative stress during extended moderate-altitude training , 1999, Wilderness & environmental medicine.

[17]  N. Chandel,et al.  Intracellular Signaling by Reactive Oxygen Species during Hypoxia in Cardiomyocytes* , 1998, The Journal of Biological Chemistry.

[18]  P. D'arbigny,et al.  EGb 761 in control of acute mountain sickness and vascular reactivity to cold exposure. , 1996, Aviation, space, and environmental medicine.

[19]  A. Cymerman,et al.  Operation Everest II: ventilatory adaptation during gradual decompression to extreme altitude. , 1990, Medicine and science in sports and exercise.

[20]  James Milledge,et al.  High altitude medicine and physiology , 1989 .

[21]  R. Bertholf,et al.  Measurement of lipid peroxidation products in rabbit brain and organs (response to aluminum exposure). , 1987, Annals of clinical and laboratory science.

[22]  B. Halliwell,et al.  Free radicals in biology and medicine , 1985 .

[23]  Jaeger Rj,et al.  Effect of hypoxia on the acute toxicity of acrylonitrile. , 1982 .

[24]  F. Tietze Enzymic method for quantitative determination of nanogram amounts of total and oxidized glutathione: applications to mammalian blood and other tissues. , 1969, Analytical biochemistry.

[25]  Oliver H. Lowry,et al.  Protein measurement with the Folin phenol reagent. , 1951, The Journal of biological chemistry.

[26]  D. Bailey,et al.  Elevated plasma cholecystokinin at high altitude: metabolic implications for the anorexia of acute mountain sickness. , 2000, High altitude medicine & biology.

[27]  Charles S. Houston,et al.  THE LAKE-LOUISE ACUTE MOUNTAIN-SICKNESS SCORING SYSTEM , 1993 .

[28]  H. Sies 4 – Hydroperoxides and Thiol Oxidants in the Study of Oxidative Stress in Intact Cells and Organs , 1985 .

[29]  Dean P. Jones 8 – The Role of Oxygen Concentration in Oxidative Stress: Hypoxic and Hyperoxic Models , 1985 .