Figure 2. OVX impairs mitochondrial function. (A, B) ATP content (A) and citrate synthase activity (B) in quadriceps muscle (n=8 mice per group). (C) Mitochondrial DNA content evaluated by the ratio of a mitochondrial encoded gene (Cox5b) and a nuclear-encoded gene (18S). (D) Relative mRNA expression of genes involved in mitochondrial biogenesis. (E) Extracellular flux analysis in EDF fiber from Sham or OVX mice (n=6). OCR was measured before (basal) and after successive addition of oligomycin (O) to determine ATP-linked respiration, carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP, F) to examine the maximal respiration, rotenone along with antimycin (R/A) to assess non-mitochondrial respiration. (F) Average OCR values were compared between Sham and OVX mice. Data are means ± SEM. *P<0.05, **P<0.01; unpaired two-tailed Student’s t-test. (G) The levels of OXPHOS proteins in mitochondrial fraction. (H) Western blot analysis for NCoR1 and PGC1α/β. (I, J) The mRNA (I) and protein (J) expressions of ERR and PPARδ.