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.
Eight subjects were placed in a decompression chamber for 31 days at pressures from sea level (SL) to 8848 m altitude equivalent. Whole blood lipid peroxidation (LP) was increased at 6000 m by a mean of 23% (P<0.05), at 8000 m by 79% (P<0.01) and at 8848 m by 94% (P<0.01). (All figures are means.) Two days after return to sea level (RSL), it remained high, by 81% (P<0.01), while corresponding erythrocyte GSH/GSSG ratios decreased by 31, 46, 49, 48%, respectively (each P<0.01). Erythrocyte SOD and plasma ascorbate did not change significantly. At sea level, maximal exercise induced a 49% increase in LP (P<0.01), and a 27% decrease in erythrocyte GSH/GSSG ratio relative to resting values (P<0.05). At 6000 m, the LP was enhanced further from 23 (P<0.05) to 66% (P<0.01), and after RSL from 81 (P<0.01) to 232% (P<0.01), while pre-exercise GSH/GSSG ratios did not change significantly. Exercise did not change plasma ascorbate relative to sea level or to 6000 m, but decreased after RSL by 32% (P<0.01). These findings suggest that oxidative stress is induced by prolonged hypobaric hypoxia, and is maintained by rapid return to sea level, similar to the post-hypoxic re-oxygenation process. It is increased by physical exercise.
Joanny
P
P
INSERM U 501, Interactions Fonctionnelles en Neuroendocrinologie, Institut Jean Roche, Faculté de Médecine de Marseilles, France.
Steinberg
J
J
Robach
P
P
Richalet
J P
JP
Gortan
C
C
Gardette
B
B
Jammes
Y
Y
D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D000531:Altitude; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology; D004912:Erythrocytes / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005602:France; D005978:Glutathione / Q000097:blood; D006400:Hematocrit; D006801:Humans; D006931:Hyperbaric Oxygenation; D000860:Hypoxia / Q000097:blood; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D012016:Reference Values; D012146:Rest / Q000502:physiology*; D012720:Severity of Illness Index; D013482:Superoxide Dismutase / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid