Intrathymic and intrasplenic oxidative stress mediates thymocyte and splenocyte damage in acutely exercised mice.
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.
Azenabor
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Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.
Hoffman-Goetz
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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
D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; D014527:Uric Acid; D002374:Catalase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid