title: Exercise-induced elevation in plasma oxidative generating capability augments the temporal inflammatory response stimulated by lipopolysaccharide.
abstract: Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may improve immune capability. We examined whether exercise-induced increases in the plasma oxidative generating capability enhance immune responsiveness to potential pathogens. Twelve individuals underwent a 30-min row and pre and post-exercise bloods were collected for oxidative stress and immune assessment. We found that exercise induced a transient increase in plasma carbonyls (3.2-5.3 nmol/mg protein) and creatine kinase activity (0.5-1.2 absorbance/min/mg protein) and that lipopolysaccharide (LPS) stimulation (0.5-24 h) of pre- and post-exercise blood augmented temporal tumour necrosis factor-alpha (TNFalpha) secretion. Further characterisation of plasma using a modified dihydro-2',7'-dichlorohydrofluorescein (DCF) assay revealed that addition of a sub-threshold of hydrogen peroxide to post-exercise (and not pre-exercise) plasma caused a sixfold increase in the radical oxygen species (ROS) generating capability after 15 min (555 +/- 131 to 3607 +/- 488 change in fluorescent intensity [DeltaFI]), which was inhibited using 60 mM N-acetyl-L: -cysteine (920 +/- 154 DeltaFI). Furthermore, cell experiments revealed that LPS stimulation of either THP-1 cells pre-incubated with post-exercise plasma or peripheral blood mononuclear cells pre-treated with pro-oxidants, modulated the temporal secretion of key cytokines that regulate the initiation, progression and resolution of an inflammatory response. These results indicate that exercise-induced changes in plasma parameters (e.g. oxidative generating capability-dependent or independent of inflammatory mediators) augment the temporal LPS response and support the notion that repeated transient oxidative stress (such as that induced by regular exercise) is important for a "healthy" immune system.
authors.affiliation: Functional Food and Health Group, The New Zealand Institute of Plant and Food Research Ltd., Private Bag 3123, East Street, Hamilton, New Zealand. rhurst@hortresearch.co.nz
authors.forename: Suzanne Maria
authors.initials: SM
authors.lastname: Hurst
authors.forename: K A
authors.initials: KA
authors.lastname: Lyall
authors.forename: R D
authors.initials: RD
authors.lastname: Hurst
authors.forename: L M
authors.initials: LM
authors.lastname: Stevenson
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology*; D007249:Inflammation / Q000139:chemically induced* / Q000276:immunology*; D008070:Lipopolysaccharides; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects / Q000276:immunology*; D010100:Oxygen / Q000097:blood* / Q000276:immunology*; D010101:Oxygen Consumption / Q000187:drug effects / Q000276:immunology*; D005082:Physical Exertion
chemical_list: D008070:Lipopolysaccharides; D010100:Oxygen