Recent progress in analysis of intermediary metabolism by ex vivo 13C NMR

Advanced imaging technologies, large-scale metabolomics, and the measurement of gene transcripts or enzyme expression all enable investigations of intermediary metabolism in human patients. Complementary information about fluxes in individual metabolic pathways may be obtained by ex vivo C-13 NMR of blood or tissue biopsies. Simple molecules such as C-13-labeled glucose are readily administered to patients prior to surgical biopsies, and C-13-labeled glycerol is easily administered orally to outpatients. Here, we review recent progress in practical applications of C-13 NMR to study cancer biology, the response to oxidative stress, gluconeogenesis, triglyceride synthesis in patients, as well as new insights into compartmentation of metabolism in the cytosol. The technical aspects of obtaining the sample, preparing material for analysis, and acquiring the spectra are relatively simple. This approach enables convenient, valuable, and quantitative insights into intermediary metabolism in patients.