Figure 2.

Age-dependent mitochondrial dysfunction in the skeletal muscle of SAMP8 mice. (A) Western blot analysis of the mitochondrial respiratory chain (MRC) subunits ATP5A (complex V), UQCRC2 (complex III), MTCOI (complex IV), SDHB (complex II), and NDUFB8 (complex I) at different ages. The quantification of each signal was normalized to the amount of GAPDH and represented below the images. (B–F) Enzymatic activities of MRC complex I (CI), succinate-coenzyme Q reductase (CoQR) and succinate dehydrogenase (SDH) activities of complex II (CII), complex IV (CIV), and citrate synthase activity were measured at different ages. All color codes as in (A). Statistical analysis was performed with one-way ANOVA and Tukey’s multiple comparison test. Error bars represent SEM; n=4 mice/group (A) and n=6 mice/group (B–F); *p < 0.05, **p < 0.01, ***p < 0.001.