Is There a Metabolic Program in the Skeletal Muscle of Obese Individuals?

Figure 1

Comparison of insulin signal transduction and fatty acid oxidation in intact skeletal muscle and human skeletal muscle cells raised in culture (HSkMC) from lean and severely obese donors. Data in the graphs were calculated from mean values in the cited papers and nonobese control values used as 100%. (a) Insulin-stimulated tyrosine phosphorylation of IRS-1 (Phos-IRS-1) [14, 43, 44]. (b) Insulin-stimulated Akt phosporylation (Phos-Akt) [15, 43, 44]. (c) IRS-1 serine 312 phosphorylation (S312-IRS-1) [20, 43, 44]. (d) Complete fatty acid oxidation as determined from labeled CO₂ production from ¹⁴C labeled palmitate (CO₂) [25, 27, 43, 45]. (e) Incomplete fatty acid oxidation from calculating the ¹⁴C from labeled palmitate remaining in the acid soluble metabolite fraction divided by labeled CO₂ production (ASM/CO₂) [27, 43, 45]. (f) Partitioning between lipid synthesis and fatty acid oxidation (synthesis/CO₂) [25, 30, 43, 45].

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