Plasma antioxidant capacity in highland subjects exposed at 5200 meters of altitude

Abstract

Abstract. Human exposure to high altitude conditions (reduced barometric pressure) leads to the formation of free radicals, which could be a major cause of altitude sickness. In the present study the total antioxidant capacity (TAC) was measured by two methods, FRAP (ferric reducing antioxidant power) and ABTS (2,2 '-azino-bis-3-6-sulfonic acid ethylbenzotiazolin acid) in the blood plasma samples of 15 non-smoking Bolivians (10 men and 5 women), who were exposed to large changes in altitude from 3,600 to 5,200 meters. The average antioxidant activity for ABTS at 3600 m was 560 µmol Trolox Equivalent./l of plasma and for FRAP 569 µmol Trolox Equivalent./l of plasma.. .After exposure to 5200 m, the ABTS and FRAP showed an increment in average of 602 µmol Trolox Equivalent./l of plasma and 642 µmol Trolox Equivalent./l of plasma. Both methods showed a high linear correlation for all samples. After exposure of subjects to extreme altitude, the results showed a significant increase in the level of antioxidants in blood plasma samples especially for the FRAP method.