FIGURE 5.

ERRγ heterozygous mice have lower exercise capacity and impaired mitochondrial oxidative metabolism. A, ERRγ mRNAs are decreased in gastrocnemius muscle of ERRγ heterozygous (HET) mice as compared with controls (WT) (n = 4–5 mice per group). B, protein levels for ERRγ are decreased in brown adipose, heart, kidney, and muscle from ERRγ heterozygous mice and corresponding littermate control mice. Nuclear extract was used for protein analysis. Distance run (C) and work performed (D) by ERRγ heterozygous mice are compared with WT mice on a treadmill (n = 12 mice per group). E, peak oxidative capacity assessed in ERRγ heterozygous mice on a treadmill (n = 7–8 mice per group) under a peak VO² protocol. F, citrate synthase activity in gastrocnemius muscle of ERRγ heterozygous mice. Mice were 12 weeks of age (n = 4–5 mice per group). G, mitochondrial gene expression in gastrocnemius muscle of ERRγ heterozygous mice. Mice utilized for these analyses were the same as in F above. Data are presented as mean ± S.E. Statistical significance is indicated as follows: *, p < 0.05; **, p < 0.01; ***, p < 0.005; ****, p < 0.001.