Fig. 2

Time courses of ¹³C enrichment of central metabolites in mouse livers fed with ¹³C₆-glucose enriched liquid diet. WT NSG mice were necropsied at 0, 12, 36, and 48 h (n = 3 at each time point) after feeding with the ¹³C₆-glucose liquid diet. Time courses of the fractional enrichments of ¹³C isotopologues (denoted as 1-15, where the number denotes the number of ¹³C atoms present) of key metabolites extracted from the liver were determined by IC-UHR-FTMS. Values represent mean ± SEM (n = 3). Fractional enrichment in the ¹³C₁ to ¹³C₃ isotopologues (1-3) of the glycolytic products 1,3-bisphosphoglycerate (1,3-BPG), 3-phosphoglycerate (3-PG) and lactate (a-c, main panels and insets with expanded Y-scale for the ¹³C₁ and ¹³C₂ isotopologues) reached steady state by 12 h. Fractional enrichment of the ¹³C isotopologues in the Krebs cycle products citrate d, succinate e, and malate f, as well as pyrimidine nucleotide UTP g also reached steady state by 12 h. However the fractional enrichment in some ¹³C isotopologues of ATP (1-7 in h), NADH (7,10 in i), and uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc; 6, 8 in j) continued to rise during the 48 h period of tracer feeding