title: Antioxidants attenuate the plasma cytokine response to exercise in humans.
abstract: Exercise increases plasma TNF-alpha, IL-1beta, and IL-6, yet the stimuli and sources of TNF-alpha and IL-1beta remain largely unknown. We tested the role of oxidative stress and the potential contribution of monocytes in this cytokine (especially IL-1beta) response in previously untrained individuals. Six healthy nonathletes performed two 45-min bicycle exercise sessions at 70% of Vo(2 max) before and after a combination of antioxidants (vitamins E, A, and C for 60 days; allopurinol for 15 days; and N-acetylcysteine for 3 days). Blood was drawn at baseline, end-exercise, and 30 and 120 min postexercise. Plasma cytokines were determined by ELISA and monocyte intracellular cytokine level by flow cytometry. Before antioxidants, TNF-alpha increased by 60%, IL-1beta by threefold, and IL-6 by sixfold secondary to exercise (P < 0.05). After antioxidants, plasma IL-1beta became undetectable, the TNF-alpha response to exercise was abolished, and the IL-6 response was significantly blunted (P < 0.05). Exercise did not increase the percentage of monocytes producing the cytokines or their mean fluorescence intensity. We conclude that in untrained humans oxidative stress is a major stimulus for exercise-induced cytokine production and that monocytes play no role in this process.
authors.affiliation: Department of Critical Care and Pulmonary Services, University of Athens Medical School, Evangelismos Hospital, GR-10675 Athens, Greece. tvassilakopoulos@yahoo.com
authors.forename: Theodoros
authors.initials: T
authors.lastname: Vassilakopoulos
authors.forename: Maria-Helena
authors.initials: MH
authors.lastname: Karatza
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Katsaounou
authors.forename: Androniki
authors.initials: A
authors.lastname: Kollintza
authors.forename: Spyros
authors.initials: S
authors.lastname: Zakynthinos
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000328:Adult; D000493:Allopurinol / Q000494:pharmacology; D000963:Antimetabolites / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D003402:Creatine Kinase / Q000097:blood; D016207:Cytokines / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D008297:Male; D009000:Monocytes / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000097:blood; D014801:Vitamin A / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D000963:Antimetabolites; D000975:Antioxidants; D016207:Cytokines; D016166:Free Radical Scavengers; D007375:Interleukin-1; D017382:Reactive Oxygen Species; D014801:Vitamin A; D014810:Vitamin E; D000493:Allopurinol; D003402:Creatine Kinase; D001205:Ascorbic Acid; D000111:Acetylcysteine