Institute of Sport Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Nitric Oxide. 2010 Sep 15;23(2):128-35. doi: 10.1016/j.niox.2010.05.003. Epub 2010 May 6.
Several studies suggest that exercise is associated with elevated oxidative stress which diminishes NO bioavailability. The aim of the present study was to investigate a potential link between NO synthesis and bioavailability and oxidative stress in the circulation of subjects performing high-intensive endurance exercise. Twenty-two male healthy subjects cycled at 80% of their maximal workload. Cubital venous blood was taken before, during and after exercise, and heparinized plasma was generated. Plasma concentrations of nitrite and nitrate were quantified by GC-MS and of the oxidative stress biomarker 15(S)-8-iso-PGF(2alpha) by GC-MS/MS. pH and pCO(2) fell and HbO(2) increased upon exercise. The duration of the 80% phase (d80) was 740+/-210s. Subjects cycled at 89.2+/-3.3% of their peak oxygen uptake. Plasma concentration of nitrite (P<0.01) and 15(S)-8-iso-PGF(2alpha) (P<0.05) decreased significantly during exercise. At the end of exercise, plasma nitrite concentration correlated positively with d80 and performed work (w80) (each P<0.05). Changes in nitrate concentration also correlated positively with d80 (P<0.05) and w80/kg (P<0.01). These findings provide evidence of a favorable effect of nitrite on high-intensive endurance exercise. The lack of association between 15(S)-8-iso-PGF(2alpha) and NO bioavailability (nitrite concentration) and NO biosynthesis (nitrate concentration) suggest that oxidative stress, notably lipid peroxidation, is not linked to the l-arginine/NO pathway in healthy male subjects being on endurance exercise.
几项研究表明，运动与氧化应激升高有关，而氧化应激会降低 NO 的生物利用度。本研究旨在探讨高强度耐力运动受试者循环中 NO 合成和生物利用度与氧化应激之间的潜在联系。22 名健康男性受试者以 80%的最大工作量进行自行车运动。在运动前、运动中和运动后采集肘静脉血，并生成肝素化血浆。通过 GC-MS 定量测定血浆中亚硝酸盐和硝酸盐的浓度，通过 GC-MS/MS 测定氧化应激生物标志物 15(S)-8-iso-PGF(2alpha)的浓度。运动时 pH 和 pCO2 下降，HbO2 增加。80%阶段（d80）的持续时间为 740+/-210s。受试者以 89.2+/-3.3%的峰值摄氧量进行自行车运动。运动过程中亚硝酸盐（P<0.01）和 15(S)-8-iso-PGF(2alpha)（P<0.05）的血浆浓度显著下降。运动结束时，血浆中亚硝酸盐浓度与 d80 和做功（w80）呈正相关（各 P<0.05）。硝酸盐浓度的变化也与 d80 呈正相关（P<0.05）和 w80/kg（P<0.01）呈正相关。这些发现为亚硝酸盐对高强度耐力运动的有益影响提供了证据。15(S)-8-iso-PGF(2alpha)与 NO 生物利用度（亚硝酸盐浓度）和 NO 合成（硝酸盐浓度）之间缺乏关联表明，在进行耐力运动的健康男性受试者中，氧化应激，特别是脂质过氧化，与 l-精氨酸/NO 途径无关。
