Reduction of myotube diameters by LA. (A – C) When we treated myotubes with lactate (LA, 8 mM) for 24 h, mean diameter of LA treated myotubes was significantly lower than control myotubes. ***p<0.001 vs. control (Cont) by unpaired t-test. (D) When we prepared the subcellular fraction (for details, see Method 2.4.), LA treatment for 24 h increased the nuclear translocation of FOXO3a, while LA overload for 1 h did not change the level of nuclear FOXO3a.