Fig. 3
From: Metabolic substrate utilization in stress-induced immune cells
Assessing cellular metabolism with stable isotope-labeled substrates. a 13C labeling patterns of TCA cycle metabolites resulting from utilization of 1,2-13C2-glucose (upper left), 13C6-glucose (upper right), and 13C5-glutamine (lower left). Depending on the substrate used, further conclusions can be drawn on the involvement of the PPP or the cycling within the TCA cycle. b 13CO2 production in PBMCs from a porcine model of acute subdural hematoma at MP before (MP1), 12 h (MP2), and 24 h (MP3) after hematoma induction. 5 × 106 PBMCs/mL were incubated in chemically identical RPMI media containing either 1,2-13C2-glucose, 13C6-glucose, or 13C5-glutamine. Supernatant was transferred to airtight vials and acidified to release CO2 into the gas phase where 13CO2 enrichment was determined by gas chromatography-mass spectrometry. Data are presented as median and interquartile range; ***p < 0.0001 according to a 2-way ANOVA and a Sidak’s multiple comparisons test, n = 5–6. Abbreviations: CO2, carbon dioxide; MP, measurement timepoint; PBMCs, peripheral blood mononuclear cells; PPP, pentose phosphate pathway; TCA, tricarboxylic acid cycle