Redox modulation of maximum force production of fast- and slow-twitch skeletal muscles of rats and mice

Abstract

We used intact fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus muscles from rats and mice to test the hypothesis that exogenous application of an oxidant would increase maximum isometric force production (Po) of slow-twitch muscles to a greater extent than fast-twitch skeletal muscles. Exposure to an oxidant, hydrogen peroxide (H2O2; 100 μM to 5 mM, 30 min), affected Po of rat muscles in a time- and dose-dependent manner. Po of rat soleus muscles was increased by 8 ± 1 (SE) and 14 ± 1% (P < 0.01) after incubation with 1 and 5 mM H2O2, respectively, whereas in mouse soleus muscles Po was only increased after incubation with 500 μM H2O2. Po of rat EDL muscles was affected by..