Department of Physiology, University of Kentucky, Lexington, KY 40536-0298, USA.
Med Sci Sports Exerc. 2011 Jun;43(6):1025-31. doi: 10.1249/MSS.0b013e3182019a78.
Reactions involving thiol biochemistry seem to play a crucial role in skeletal muscle fatigue. N-acetylcysteine amide (NACA) and L-ergothioneine (ERGO) are thiol-based antioxidants available for human use that have not been evaluated for effects on muscle fatigue.
To test the hypothesis that NACA and ERGO delay skeletal muscle fatigue.
We exposed mouse diaphragm fiber bundles to buffer (CTRL), NACA, ERGO, or N-acetylcysteine (NAC; positive control). Treatments were performed in vitro using 10 mM for 60 min at 37 °C. After treatment, we determined the muscle force-frequency and fatigue characteristics.
The force-frequency relationship was shifted to the left by ERGO and to the right by NACA compared with CTRL and NAC. Maximal tetanic force was similar among groups. The total force-time integral (FTI; N · s · cm) during the fatigue trial was decreased by NACA (420 ± 35, P < 0.05), unaffected by ERGO (657 ± 53), and increased by NAC (P < 0.05) compared with CTRL (581 ± 54). The rate of contraction (dF/dtMAX) during the fatigue trial was not affected by any of the treatments tested. NAC, but not NACA or ERGO, delayed the slowing of muscle relaxation (dF/dtMIN) during fatigue.
In summary, NACA and ERGO did not delay skeletal muscle fatigue in vitro. We conclude that these antioxidants are unlikely to improve human exercise performance.
涉及巯基生物化学的反应似乎在骨骼肌疲劳中起着至关重要的作用。N-乙酰半胱氨酸酰胺（NACA）和 L-麦角硫因（ERGO）是两种可用于人体的巯基抗氧化剂，尚未评估它们对肌肉疲劳的影响。
验证 NACA 和 ERGO 可延迟骨骼肌疲劳的假说。
我们将小鼠横膈膜纤维束暴露于缓冲液（CTRL）、NACA、ERGO 或 N-乙酰半胱氨酸（NAC；阳性对照）中。在 37°C 下以 10mM 处理 60 分钟，在体外进行处理。处理后，我们测定肌肉的力-频率和疲劳特征。
与 CTRL 和 NAC 相比，ERGO 使力-频率关系向左移位，NACA 使力-频率关系向右移位。各组的最大强直力相似。疲劳试验中的总力-时间积分（FTI；N·s·cm）因 NACA 而降低（420±35，P<0.05），不受 ERGO（657±53）影响，且因 NAC 而增加（P<0.05），与 CTRL（581±54）相比。疲劳试验期间的收缩速率（dF/dtMAX）不受任何测试处理的影响。NAC 但不是 NACA 或 ERGO 可延迟肌肉松弛期间的 dF/dtMIN 减慢。
总之，NACA 和 ERGO 未延迟体外骨骼肌疲劳。我们得出结论，这些抗氧化剂不太可能改善人类运动表现。
