Figure 3.

Stable isotope flux analysis of PPARδ agonist-treated 3T3-L1 adipocytes. (a) Graphs showing the M+1/M isotope ratio ¹³C enrichment of lactate, glutamate and succinate analyzed by GC-MS of the aqueous fraction and M+1/M isotope ratio ¹³C enrichment of palmitic acid analyzed by GC-MS of the organic fraction from control (n = 6) and PPARδ agonist-treated (n = 6) 3T3-L1 cells incubated with 1-¹³C glucose. *P < 0.05, **P < 0.01. The metabolites have been mapped to the glycolysis and TCA cycle metabolic pathways. Red indicates a metabolite increased in ¹³C enrichment by PPARδ activation. (b) Graphs showing the M+1/M isotope ratio ¹³C enrichment of malate, glutamate, fumarate and succinate analyzed by GC-MS of the aqueous fraction and enrichment of arachidic acid, stearic acid, palmitoleic acid, myristic acid and lauric acid analyzed by GC-MS of the organic fraction from control (n = 6) and PPARδ agonist-treated (n = 6) 3T3-L1 cells incubated with U-¹³C palmitate. *P < 0.05, **P < 0.01,***P < 0.005. Red indicates a metabolite increased, and blue indicates a metabolite decreased in ¹³C enrichment by PPARδ activation. Parent ions were used to calculate ion ratio. Error bars represent standard errors of the mean.