title: Lung oxidative stress as related to exercise and altitude. Lipid peroxidation evidence in exhaled breath condensate: a possible predictor of acute mountain sickness.
abstract: Lung oxidative stress (OS) was explored in resting and in exercising subjects exposed to moderate and high altitude. Exhaled breath condensate (EBC) was collected under field conditions in male high-competition mountain bikers performing a maximal cycloergometric exercise at 670 m and at 2,160 m, as well as, in male soldiers climbing up to 6,125 m in Northern Chile. Malondialdehyde concentration [MDA] was measured by high-performance liquid chromatography in EBC and in serum samples. Hydrogen peroxide concentration [H(2)O(2)] was analysed in EBC according to the spectrophotometric FOX(2) assay. [MDA] in EBC of bikers did not change while exercising at 670 m, but increased from 30.0+/-8.0 to 50.0+/-11.0 nmol l(-1) (P<0.05) at 2,160 m. Concomitantly, [MDA] in serum and [H(2)O(2)] in EBC remained constant. On the other hand, in mountaineering soldiers, [H(2)O(2)] in EBC under resting conditions increased from 0.30+/-0.12 mumol l(-1) at 670 m to 1.14+/-0.29 mumol l(-1) immediately on return from the mountain. Three days later, [H(2)O(2)] in EBC (0.93 +/-0.23 mumol l(-1)) continued to be elevated (P<0.05). [MDA] in EBC increased from 71+/-16 nmol l(-1) at 670 m to 128+/-26 nmol l(-1) at 3,000 m (P<0.05). Changes of [H(2)O(2)] in EBC while ascending from 670 m up to 3,000 m inversely correlated with concomitant variations in HbO2 saturation (r=-0.48, P<0.05). AMS score evaluated at 5,000 m directly correlated with changes of [MDA] in EBC occurring while the subjects moved from 670 to 3,000 m (r=0.51, P<0.05). Lung OS may constitute a pathogenic factor in AMS.
authors.affiliation: Laboratorio de Ambientes Extremos, Programa de Fisiología y Biofísica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile. oaraneda@med.uchile.cl
authors.forename: O F
authors.initials: OF
authors.lastname: Araneda
authors.forename: C
authors.initials: C
authors.lastname: García
authors.forename: N
authors.initials: N
authors.lastname: Lagos
authors.forename: G
authors.initials: G
authors.lastname: Quiroga
authors.forename: J
authors.initials: J
authors.lastname: Cajigal
authors.forename: M P
authors.initials: MP
authors.lastname: Salazar
authors.forename: C
authors.initials: C
authors.lastname: Behn
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000175:diagnosis* / Q000378:metabolism*; D001944:Breath Tests; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D008168:Lung / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009051:Mountaineering / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*
chemical_list: D008315:Malondialdehyde; D006861:Hydrogen Peroxide