School of Integrative Physiology and Athletic Training, University of Montana, Missoula, MT, USA.
School of Health and Kinesiology, University of Nebraska - Omaha, Omaha, NE, USA.
J Sports Sci. 2021 Jun;39(12):1356-1365. doi: 10.1080/02640414.2021.1872960. Epub 2021 Jan 11.
Hypobaria and hypoxia exert independent effects on oxidative stress during exercise, while combined effectson the post-exercise recovery period remain unclear.Accordingly, this study examined the recovery period during lab-simulated hypoxic and hypobaric conditions following exercise-induced oxidative stress. Participants (n=13) performed 60-minutes of cycling (70% watts max) in a normobaric normoxic environment followed by a four-hour recovery under three conditions; 1000m normobaric normoxia (NN, 675mmHg), 4400m normobaric hypoxia (NH, 675mmHg), or 4400m hypobaric hypoxia (HH, 440mmHg). Blood samples collected at Pre, Post, 2-Hours (2-HR), and 4-Hours (4-HR) post-exercise were analyzed fora potential increase in biochemical modifications of proteins(protein carbonyls, PC; 3-nitrotyrosines, 3NT) lipids (lipid hydroperoxides, LOOH; 8-isoprostanes, 8-ISO), and antioxidant capacity (FRAP, TEAC). Gene transcripts (EPAS, HMOX1, SOD2, NFE2L2) were quantified by qRT-PCR from muscle biopsies taken Pre and Post exercise. Hypoxia and hypobaria had no effect throughout recovery. Post-exercise TEAC (p=0.041), FRAP (p=0.013), and 8-ISO (p=0.044) increased, while PC (p=0.002) and 3-NT (p=0.032) were decreased. LOOH was lower in Post (p=0.018) NH trial samples. Exercise-dependent increases occurred in NFE2L2 (p=0.003), HMXO1 (p<0.001), SOD2 (p=0.046), and EPAS (p=0.038). Exercise recovery under conditions of NH and HH did not impact blood oxidative stress or redox-sensitive gene transcripts.
低压低氧对运动时的氧化应激有独立影响，而在运动后恢复期的综合影响尚不清楚。因此，本研究检测了模拟低压低氧条件下运动引起的氧化应激后的恢复期。13 名参与者在常氧常压环境下进行 60 分钟的自行车运动（70%最大瓦特），然后在以下三种条件下进行 4 小时的恢复：1000 米常氧常压（NN，675mmHg）、4400 米常氧低压（NH，675mmHg）或 4400 米低压低氧（HH，440mmHg）。运动前后（Pre、Post）、2 小时（2-HR）和 4 小时（4-HR）采集血样，分析蛋白生物化学修饰物（蛋白羰基、PC；3-硝基酪氨酸、3NT）、脂质（脂质过氧化物、LOOH；8-异前列腺素、8-ISO）和抗氧化能力（FRAP、TEAC）的潜在增加。运动前后（Pre、Post）从肌肉活检中定量 qRT-PCR 检测基因转录物（EPAS、HMOX1、SOD2、NFE2L2）。 结果显示，在恢复期间，缺氧和低压没有影响。运动后 TEAC（p=0.041）、FRAP（p=0.013）和 8-ISO（p=0.044）增加，而 PC（p=0.002）和 3-NT（p=0.032）减少。NH 试验样本中 LOOH 在 Post 时较低（p=0.018）。NFE2L2（p=0.003）、HMXO1（p<0.001）、SOD2（p=0.046）和 EPAS（p=0.038）的运动依赖性增加。NH 和 HH 条件下的运动恢复并未影响血液氧化应激或氧化还原敏感基因转录物。
