UNLABELLED: 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. PURPOSE: To test the hypothesis that NACA and ERGO delay skeletal muscle fatigue. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
UNLABELLED: 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. PURPOSE: To test the hypothesis that NACA and ERGOdelay skeletal muscle fatigue. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Brandon M Roberts; Bumsoo Ahn; Ashley J Smuder; Monsour Al-Rajhi; Luther C Gill; Adam W Beharry; Scott K Powers; David D Fuller; Leonardo F Ferreira; Andrew R Judge Journal: FASEB J Date: 2013-03-20 Impact factor: 5.191
Authors: Trace Thome; Ravi A Kumar; Sarah K Burke; Ram B Khattri; Zachary R Salyers; Rachel C Kelley; Madeline D Coleman; Demetra D Christou; Russell T Hepple; Salvatore T Scali; Leonardo F Ferreira; Terence E Ryan Journal: JCI Insight Date: 2020-12-08