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Author(s): Magalhaes, J
Ascensao, A
Marques, F
Soares, JMC
Ferreira, R
Neuparth, MJ
Duarte, JA
Title: Effect of a high-altitude expedition to a Himalayan peak (Pumori, 7,161 m) on plasma and erythrocyte antioxidant profile
Issue Date: 2005
Abstract: The effects of a high-altitude exposure were studied in six mountaineers who spent 3 weeks at an altitude range between 5,250 and 7,161 m after I week in an acclimatization trek (2,800-5,250 m). Blood drawn from the antecubital vein was collected at sea level I day before and I day after the expedition to analyse some haematological variables [haemoglobin (Hb), haematocrit (Htc) and red blood cell (RBC) count], erythrocyte antioxidant enzyme activity [superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (Gr)] and membrane fatty acid profile [monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), trans fatty acids (TRANS)]. Moreover, total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), thiol protein groups (SH), SOD, GPx and Gr were measured in plasma. High-altitude exposure induced polycythaemia, with significant increases in RBC count (5.26%), Hb concentration (4.83%) and Htc (6.26%). Furthermore, a significant increase in plasma TBARS, SOD and Gr was observed after the expedition, whereas SH, TAS and GPx decreased. Erythrocyte glutathione-cycle-related antioxidant enzyme activity was upregulated, whereas SOD activity was maintained after the expedition. In addition, despite the unchanged (MUFA+PUFA)/SFA ratio, the membrane erythrocyte fatty acid content showed a significant increase in PUFAs and a decrease in TRANS, suggesting enhanced membrane fluidity. In conclusion, it seems that high-altitude exposure, besides quantitative variations in RBC expression, induced plasma oxidative stress and damage, and significant changes in erythrocyte components, namely in antioxidant enzyme activity and membrane fatty acid profile that might modify RBC functionality.
Subject: Medicina básica
Basic medicine
Scientific areas: Ciências médicas e da saúde::Medicina básica
Medical and Health sciences::Basic medicine
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FADEUP - Artigo em Revista Científica Internacional
FFUP - Artigo em Revista Científica Internacional

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