title: Pre-exercise antioxidant enzyme activities determine the antioxidant enzyme erythrocyte response to exercise.
abstract: Free radical production increases during exercise and oxidative damage occurs in several tissues. We examined the effects of three different exercise tests on the pattern of change of erythrocyte enzyme antioxidant activities. The tests were a short maximal exercise test, a submaximal prolonged exercise test and a cycling stage during competition. The participants were amateur and professional cyclists with different training statuses and different basal erythrocyte antioxidant enzyme activities. The maximal test produced no changes in the erythrocyte antioxidant enzyme activities of amateur sportsmen. The submaximal test, performed at 80% of maximal oxygen uptake, decreased erythrocyte catalase (12%), glutathione peroxidase determined with H2O2 (14%) and glutathione reductase (16%); superoxide dismutase activity increased by about 25%. The cycling stage performed by professional cyclists increased erythrocyte catalase (29%) and glutathione reductase (10%) activities. The in vivo changes in glutathione reductase activity were confirmed by in vitro measurements: hydrogen peroxide decreased and the presence of catalase increased the activity of this enzyme. In conclusion, we suggest that the different erythrocyte antioxidant enzyme responses to diverse exercise tests can be explained by the effects of hydrogen peroxide and the superoxide anion on the antioxidant enzyme activities in erythrocytes.
authors.affiliation: Laboratori de Ciències de l'Activitat Fisica & Departament Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Balears, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Tauler
authors.forename: A
authors.initials: A
authors.lastname: Aguiló
authors.forename: P
authors.initials: P
authors.lastname: Guix
authors.forename: F
authors.initials: F
authors.lastname: Jiménez
authors.forename: G
authors.initials: G
authors.lastname: Villa
authors.forename: J A
authors.initials: JA
authors.lastname: Tur
authors.forename: A
authors.initials: A
authors.lastname: Córdova
authors.forename: A
authors.initials: A
authors.lastname: Pons
mesh_terms: D000328:Adult; D002374:Catalase / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D016166:Free Radical Scavengers / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase