Figure 4.

Skeletal muscle mitochondrial function, OXPHOS, cardiolipin, and coenzyme Q10 content are reduced, and H₂O₂ emission is elevated following 10 days of BR. (A) Mitochondrial respiratory capacity was measured in permeabilized fiber bundles and reported as O₂ flux normalized to the dry weight of the fiber bundles; n = 5 per group. (B) Mitochondrial H₂O₂ emission was measured in permeabilized fiber bundles and reported as H₂O₂ emission normalized to total OXPHOS content; n = 5 per group. (C) Skeletal muscle mitochondria oxidative phosphorylation (OXPHOS) content pre- and post-10 days of BR and representative Western blot images; n = 8–9 per group. Pre- and post-BR data are reported as fold change from pre-BR. (D) Skeletal muscle total cardiolipin and coenzyme Q10 pre- and post-10 days of BR; n = 6–7 per group. ┴ Significant group effect for HMB group pre-BR (Group Effect: p = .008, Interaction: p = .44), * Significant time effect for PI (Time Effect: p = .03, Interaction: 0.91) and EI+II (Time Effect: p = .01, Interaction: p = .96) to be reduced in both groups following BR, and † trend for time effect for PI+II (Time Effect: p = .059, Interaction: p = .71) to be reduced in both groups following BR. † trend for time effect for H₂O₂ emission to be elevated in both groups following 10 days of BR (Time Effect p = .056, Interaction: p = .61). * Significant time effect for reductions in both groups for total OXPHOS content (Time Effect: p = .002, Interaction: p = .34), complex I (Time Effect: p = .005, Interaction: p = .31), complex II (Time Effect: p = .008, Interaction: p = .32), complex III (Time Effect: p = .004, Interaction: p = .28), complex IV (Time Effect: p = .017, Interaction: p = .76) and complex V (Time Effect: p = .03, Interaction: p = .64). * Significant time effect for cardiolipin (Time Effect: p = .04, Interaction: 0.42) and † trend for time effect for coenzyme Q10 (Time Effect: p = .0577, Interaction: p = .92) to be reduced following BR. The heat map represents the log₂ fold change of all cardiolipin species during BR in the CON and HMB groups. The cardiolipin species are grouped according to the maturation status of each species. n = 5 per group. Red (up-regulated) and blue (down regulated) dots represent significantly changed metabolites during BR.