title: Erythrocyte nitric oxide availability and oxidative stress following exercise.
abstract: Growing evidence has shown that acute exercise impairs erythrocyte membrane structure and function as a consequence of increased physical and chemical stress. Erythrocyte-synthesized nitric oxide (NO) is known to modulate membrane fluidity, and its bioavailability depends on the balance between its production and scavenging by reactive oxygen species. Here, we investigated whether a maximal exercise test could affect erythrocyte NO bioavailability and oxidative stress. Twelve men (26±4 years old, V̇O2peak 44.1±4.3 mL·kg-1·min-1) performed a treadmill maximal cardiopulmonary exercise test. Blood was collected at rest and immediately after exercise for erythrocytes isolation. Maximal exercise caused an increase in erythrocytes count, haemoglobin and haematocrit levels. There was no change in L-arginine influx into erythrocytes after exercise. Yet, nitric oxide synthase activity, and thus, NO production, was increased after maximal test, as well cyclic GMP levels. In relation to biomarkers of oxidative stress, maximal test resulted in increased levels of lipid peroxidation, and diminished superoxide dismutase activity. Neither glutathione peroxidase nor catalase activity was affected by maximal test. Our findings demonstrate that the increased erythrocyte membrane rigidity caused by an acute bout of exercise may be caused, in part, by an increased lipid oxidative damage caused by ROS produced exogenously.
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Daniel Jose Matos
authors.initials: DJ
authors.lastname: Medeiros-Lima
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Antonio Claudio
authors.initials: AC
authors.lastname: Mendes-Ribeiro
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Tatiana Marlowe Cunha
authors.initials: TM
authors.lastname: Brunini
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Marcela Anjos
authors.initials: MA
authors.lastname: Martins
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Wanda Vianna
authors.initials: WV
authors.lastname: Mury
authors.affiliation: Physical Activity and Health Promotion Laboratory, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Raul Almeira
authors.initials: RA
authors.lastname: Freire
authors.affiliation: Physical Activity and Health Promotion Laboratory, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.|Salgado de Oliveira University Physical Activity Sciences Graduate Program, Rio de Janeiro, Brazil.
authors.forename: Walace David
authors.initials: WD
authors.lastname: Monteiro
authors.affiliation: Physical Activity and Health Promotion Laboratory, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.|Salgado de Oliveira University Physical Activity Sciences Graduate Program, Rio de Janeiro, Brazil.
authors.forename: Paulo Tarso Veras
authors.initials: PT
authors.lastname: Farinatti
authors.affiliation: Department of Pharmacology and Psychobiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Matsuura
mesh_terms: D000328:Adult; D004912:Erythrocytes / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D013482:Superoxide Dismutase
keywords: Reactive oxygen species; arginine; nitric oxide synthase; red blood cells