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Oxidative stress restores force loss in skeletal muscle following eccentric contractions
Author(s) -
Hernández Andrés,
Kosteritalia,
Katz Abe,
Westerblad Håkan
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.801.24
Subject(s) - eccentric , isometric exercise , contraction (grammar) , chemistry , skeletal muscle , muscle contraction , anatomy , medicine , physics , quantum mechanics
The role of oxidative stress in force recovery following eccentric contractions was examined in mouse EDL muscles. Isometric force was measured at 30, 70, and 150 Hz (0.5 ms pulse, 300 ms train) before, immediately after, and during a 60 min period following 10 eccentric contractions (stretched to 15% above optimal length during last 150 ms of 400 ms tetanus) at a train rate of 1 contraction every 4 s. Three groups were utilized: Control (C); H 2 O 2 , 100 μM was administered after the post‐eccentric contraction test; DTT, 5 mM was administered as in the H 2 O 2 condition. The force immediately after eccentric contractions was decreased by ≈50% (30 Hz), ≈55% (70 Hz), and ≈45% (150 Hz) with no significant differences between groups (p>0.05). To compare recovery, force was normalized to each frequency's force immediately after eccentric contractions (i.e., post‐eccentric contraction force=100%). The effects of H 2 O 2 and DTT on force recovery were most pronounced at 30 Hz. For instance, at 40 min normalized force was significantly higher (p<0.05) in H 2 O 2 (125±7%) and lower in DTT (73±5%) in comparison to C (101±8%). In contrast, normalized force for H 2 O 2 during 150 Hz stimulation was not significantly different from C or DTT at 40 min. These results indicate that oxidative stress is important for force recovery at low frequencies in skeletal muscle following eccentric contractions.