Figure 3. Effect of rapamycin on ATP concentration in C2C12 myoblasts and myotubes. (A) ATP concentration of C2C12 myoblasts, which were cultured for 48 h, then treated by rapamycin (100 nM) for 24 h. (B) ATP concentration of C2C12 myotubes, which were cultured for 6 d, then treated by rapamycin (100 nM) for 24 h. *, P < 0.05 control versus rapamycin-treated groups by Student’s t test.