title: Intrathymic and intrasplenic oxidative stress mediates thymocyte and splenocyte damage in acutely exercised mice.
abstract: Reactive oxygen species may contribute to apoptosis in lymphoid tissues observed after exercise. Thymic and splenic tissues excised from control mice (C) or mice immediately after (t0) or 24 h after (t24) a run to exhaustion (RTE) were assayed for biochemical indexes of oxidative stress [thymic and splenic membrane lipid peroxides, superoxide dismutase, catalase, plasma uric acid (UA), and ascorbic acid (AA)]. There were significant increases in membrane lipid peroxides in thymus (P < 0.001) and spleen (P < 0.001) in acutely exercised mice relative to controls (thymus: C = 2.74 +/- 0.80 microM; t0 = 7.45 +/- 0.48 microM; t24 = 9.44 +/-1.41 microM; spleen: C = 0.48 +/- 0.22 microM; t0 = 1.78 +/- 0.28 microM; t24 = 2. 81 +/- 0.34 microM). The thymic and splenic tissue antioxidant enzymes concentrations of superoxide dismutase and catalase were significantly lower in samples collected at t0 relative to C and t24 mice (P < 0.001). Plasma UA and AA levels were used to assess the impact of the RTE on the peripheral antioxidant pool. There was no significant change in UA levels and a significant reduction in plasma AA concentrations (P < 0.001); the reduction in plasma AA occurred at t24 (6.53 +/- 1.64 microM) relative to t0 (13.11 +/- 0. 71 microM) and C (13.26 +/- 1.2 microM). These results suggest that oxidative damage occurs in lymphoid tissues after RTE exercise and that such damage may contribute to lymphocyte damage observed after acute exercise.
authors.affiliation: Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
authors.forename: A A
authors.initials: AA
authors.lastname: Azenabor
authors.forename: L
authors.initials: L
authors.lastname: Hoffman-Goetz
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000097:blood; D002374:Catalase / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008214:Lymphocytes / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013154:Spleen / Q000166:cytology* / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology* / Q000502:physiology*; D014527:Uric Acid / Q000097:blood
chemical_list: D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; D014527:Uric Acid; D002374:Catalase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid