Figure 1. Effects of Leu (0.5 mM or 10 mM), KIC (0.5 mM or 10 mM), and HMB (50 μM) on (A) protein degradation, (B) media 3-MeHis, (C) MAFbx protein expression, (D) MuRF1 protein expression, and (E) cell apoptosis in C2C12 myotubes. Results are expressed as mean ± SEM. Different letters (a, b, c) indicated significant differences (P < 0.05). CON, control; HMB, β-hydroxy-β-methyl butyrate; KIC, α-ketoisocaproate; Leu, leucine.