Research Paper Volume 11, Issue 24 pp 11922—11936

Suppression of protein degradation by leucine requires its conversion to β-hydroxy-β-methyl butyrate in C2C12 myotubes

Figure 3. Effects of Leu (0.5 mM or 10 mM), KIC (0.5 mM or 10 mM), and HMB (50 μM) on (AB) oxygen consumption rate (OCR) of C2C12 myotubes and (C) protein expression of AMPKα and PGC-α. (A) Represents mitochondrial OCR curves obtained from different conditions. (B) Basal, basal respiration; H+ leak; ATP, ATP production; Max, maximum respiration; SRC, spare respiration capacity; and NMR, non-mitochondrial respiration of C2C12 myotubes under different treatments, respectively. 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.