Mathematical modelling for the generation of L-[3-2H,3-13C]lactic acid isotopomers by erythrocytes exposed to either D-[1-13C]glucose or D-[6-13C]glucose in the presence of 2H2O.

The production of C3-trisdeuterated, bisdeuterated, monodeuterated or non-deuterated L-[3-13C]lactate by human erythrocytes exposed to either D-[1-13C]glucose or D-[6-13C]glucose in the presence of 2H2O can be assessed by 13C NMR spectroscopy. Such a deuteration may occur at the level of the reactions catalyzed by phosphoglucoisomerase, phosphomannoisomerase, pyruvate kinase and glutamate-pyruvate transaminase. In this report, a mathematical model is proposed for the analysis of experimental data. It allows to estimate the relative extent of deuteration at each step of D-glucose metabolism. This approach may thus provide novel information on the extent of back-and-forth interconversion of either hexose 6-phosphates in both the phosphoglucoisomerase and phosphomannoisomerase reactions or pyruvate and L-alanine in the reaction catalyzed by glutamate-pyruvate transaminase.