@article {Rousseau:2006:0095-6562:551, title = "Plasma Glutathione Peroxidase Activity as a Potential Indicator of Hypoxic Stress in Breath-Hold Diving", journal = "Aviation, Space, and Environmental Medicine", parent_itemid = "infobike://asma/asem", publishercode ="asma", year = "2006", volume = "77", number = "5", publication date ="2006-05-01T00:00:00", pages = "551-555", itemtype = "ARTICLE", issn = "0095-6562", url = "https://www.ingentaconnect.com/content/asma/asem/2006/00000077/00000005/art00012", keyword = "ischemia/reperfusion, oxidative stress, breath-hold, antioxidant enzyme", author = "Rousseau, Anne-Sophie and Richer, Caroline and Richard, Marie-Jeanne and Favier, Alain and Margaritis, Ir{\‘e}ne", abstract = "Rousseau A-S, Richer C, Richard M-J, Favier A, Margaritis I. Plasma glutathione peroxidase activity as a potential indicator of hypoxic stress in breath-hold diving. Aviat Space Environ Med 2006; 77:551555. Introduction: Diving mammals can cope with oxidants which are produced in excess during the reoxygenation of hypoxic tissues. This study addresses the question of whether antioxidants can adapt and whether it allows humans to tolerate the hypoxic stress induced by a single breath-holding in the course of a dynamic diving exercise and protect them from oxidative insult. Methods: There were 20 male subjects who performed submaximal apnea dynamic diving (ADD). Nine control subjects stayed out of the water and breathed normally. Venous blood samples were collected 1 h before and immediatly after ADD. Results: ADD induced a significant increase in plasma glutathione peroxidase (GPx-3) activity (from 397.5 \textpm 44.4 to 410 \textpm 43 U \textperiodcentered L1), blood reduced glutathione (GSH) (from 1060 \textpm 302 to 1292 \textpm 213 mol \textperiodcentered L1), and in plasma creatine kinase activity (from 215 \textpm 137 to 235 \textpm 152 U \textperiodcentered L1). The activity of the erythrocyte superoxide dismutase and glutathione peroxidase, as well as the blood oxidized glutathione and the plasma thiobarbituric acid reactive substances concentrations, were maintained at their basal level. The level of training, characterized by the duration and distance of the dive, had no effect on the markers used. Conclusion: GPx-3 and GSH could constitute the most readily mobilizable antioxidants that would then contribute to the buffering against a sudden increase in the generation of radical oxygen species. These biomarkers could be used as tools for establishing oxidative stress during hypoxia. The response of GPx-3 to hypoxia could be of physiological relevance.", }