Figure 3.

VitA does not impair skeletal muscle mitochondrial function and morphological structure in DIO. Data are reported as mean values ± SE. Two-way ANOVA was performed to analyze differences by HFD feeding and VitA. Results of post-hoc analyses for each comparison are summarized by symbols as defined: # p<0.05 for HFD feeding and $ p<0.05 for VitA. No significant effect for the interaction between HFD feeding and VitA was determined. V_ADP of isolated skeletal muscle mitochondria with (A) palmitoyl-carnitine (#) and (B) pyruvate (#) each combined with malate as substrates (n=6-8). (C) Citrate synthase and (D) HADH (#) activity in skeletal muscle (n=7-8). (E) Representative immunoblots and (F) densitometric analysis of NDUFA9 (#, $), SDHA (#, $), ATP5A (#, $), MnSOD (#),UCP3 (#), and 4-HNE normalized to Vinculin. Data are presented as fold change relative to NCD (assigned as 1.0; dashed line), n=6. (G) mRNA expression of transcripts involved in mitochondrial energetics presented as fold change relative to NCD and normalized to Rps16 (assigned as 1.0; dashed line), n=8. (H) Representative WGA and H&E stains of skeletal muscle sections (scale bars: 50 μm each). (I) Mean cross-sectional area of skeletal muscle fibers presented as percentage of total fibers (# for 4001-5000 µm², n=5-6). (J) mRNA expression of transcripts involved in organ fibrosis presented as fold change relative to NCD and normalized to Rps16 (assigned as 1.0; dashed line), n=8. *p < 0.05 vs. normocaloric diet same VitA availability, † p<0.05 vs. VitA sufficiency same caloric diet.