Application of Stable Isotope Labelling in Cell Culture Experiments: [2-13C]pyruvate as Novel and Superior Substrate for in Vitro Metabolic Studies in Primary Mouse Hepatocytes

Sven Gottschalk¹, Dieter Leibfritz², Claudia Zwingmann^1,2, Marc Bilodeau¹

Application of stable isotope labeling in vitro is a potent technique to study metabolic pathways and fluxes. We applied [2-¹³C]pyruvate on primary mouse hepatocyte cultures to compare its usefulness for metabolic studies and flux analysis with other labeled substances. Our results show: [2-¹³C]pyruvate was metabolized by lactate dehydrogenase, alanine-/aspartate-aminotransferase, malic enzyme, PC, PDH and subsequent metabolic pathways through the TCA-cycle. Taken together with our previous findings, we conclude that [2-¹³C]pyruvate is a versatile physiological substrate to study hepatocellular pathways and the de novo synthesis of major metabolites in these cells under normal and pathological conditions.