Figure 1.

Muscle-specific overexpression of PGC-1α increased mitochondrial preference for lipid substrate. MCK-PGC1α transgenic mice and NT littermates were fed an HFD for 6 weeks prior to experiments. Mitochondria isolated from gastrocnemius muscles were used to assess oxidation of 200 μmol/L [¹⁴C]palmitate to CO₂ (A) and ASM (B), measured in the absence (FA) or presence (FA+Pyr) of 1 mmol/L pyruvate. Whole-body energy metabolism and exercise performance were assessed during a graded treadmill test during which oxygen consumption (C), distance to exhaustion (D), RER (E), and average RER (F) were evaluated. Values are means ± SEM for 6–9 mice per group. *P < 0.05 between genotypes, **P < 0.005 between genotypes. FA, fatty acid; Pyr, pyruvate.