Davison Gareth W, Morgan Rhian M, Hiscock Natalie, Garcia Juan M, Grace Fergal, Boisseau Natalie, Davies Bruce, Castell Linda, McEneny Jane, Young Ian S, Hullin David, Ashton Tony, Bailey Damian M
School of Health Sciences, University of Ulster Jordanstown, Newtownabbey, County Antrim BT37 OQB, UK.
Clin Sci (Lond). 2006 Jan;110(1):133-41. doi: 10.1042/CS20050135.
Maximal exercise in normoxia results in oxidative stress due to an increase in free radical production. However, the effect of a single bout of moderate aerobic exercise performed in either relative or absolute normobaric hypoxia on free radical production and lipid peroxidation remains unknown. To examine this, we randomly matched {according to their normobaric normoxic VO2peak [peak VO2 (oxygen uptake)]} and assigned 30 male subjects to a normoxia (n = 10), a hypoxia relative (n = 10) or a hypoxia absolute (n = 10) group. Each group was required to exercise on a cycle ergometer at 55% of VO2peak for 2 h double-blinded to either a normoxic or hypoxic condition [FiO2 (inspired fraction of O2) = 0.21 and 0.16 respectively]. ESR (electron spin resonance) spectroscopy in conjunction with ex vivo spin trapping was utilized for the direct detection of free radical species. The main findings show that moderate intensity exercise increased plasma-volume-corrected free radical and lipid hydroperoxide concentration (pooled rest compared with exercise data, P < 0.05); however, there were no selective differences between groups (statexgroup interaction, P > 0.05). The delta change in free radical concentration was moderately correlated with systemic VO2 (r2 = 0.48, P < 0.05). The hyperfine coupling constants recorded from the ESR spectra [aN = 13.8 Gauss, and a(H)beta = 1.9 Gauss; where 1 Gauss = 10(-4) T (telsa)] are suggestive of oxygen-centred free radical species formed via the decomposition of lipid hydroperoxides. Peripheral leucocyte and neutrophil cells and total CK (creatine kinase) activity all increased following sustained exercise (pooled rest compared with exercise data, P < 0.05), but no selective differences were observed between groups (state x group interaction, P > 0.05). We conclude that a single bout of moderate aerobic exercise increases secondary free radical species. There is also evidence of exercise-induced muscle damage, possibly caused by the increase in free radical generation.
常氧下的最大运动由于自由基产生增加而导致氧化应激。然而，在相对或绝对常压性低氧条件下进行单次中等强度有氧运动对自由基产生和脂质过氧化的影响仍不清楚。为了对此进行研究，我们根据他们的常压常氧下的最大摄氧量峰值[峰值摄氧量（氧摄取量）]进行随机匹配，并将30名男性受试者分为常氧组（n = 10）、相对低氧组（n = 10）或绝对低氧组（n = 10）。每组受试者均需在功率自行车上以最大摄氧量峰值的55%进行运动2小时，且对常氧或低氧条件双盲[分别为吸入氧分数（FiO2）= 0.21和0.16]。采用电子自旋共振（ESR）光谱结合离体自旋捕获技术直接检测自由基种类。主要研究结果表明，中等强度运动增加了血浆容量校正后的自由基和脂质氢过氧化物浓度（静息数据与运动数据合并比较，P < 0.05）；然而，各组之间没有显著差异（状态×组间交互作用，P > 0.05）。自由基浓度的变化量与全身摄氧量呈中度相关（r2 = 0.48，P < 0.05）。从ESR光谱记录的超精细偶合常数[aN = 13.8高斯，a(H)β = 1.9高斯；其中1高斯 = 10(-4)特斯拉（T）]表明存在通过脂质氢过氧化物分解形成的以氧为中心的自由基种类。持续运动后外周血白细胞、中性粒细胞和总肌酸激酶（CK）活性均增加（静息数据与运动数据合并比较，P < 0.05），但各组之间未观察到显著差异（状态×组间交互作用，P > 0.05）。我们得出结论，单次中等强度有氧运动增加了继发性自由基种类。也有证据表明运动诱导了肌肉损伤，可能是由自由基生成增加所致。
