title: The complex isotopologue space of glucose as a framework for the study of human intermediary metabolism.
abstract: The positional distributions of stable isotopes in metabolites provide specific fingerprints of the pathways and fluxes that have occurred in the organisms under study. In particular, modern nuclear magnetic resonance (NMR) spectroscopy enables the detailed assignment of isotope patterns in natural products, for example, in metabolites obtained from labelling experiments using (13)C-enriched precursors, such as glucose, acetate or CO2. In this study, the transient (13)C-isotopologue composition of blood glucose from an adult human volunteer after intravenous supply of [U-(13)C6]glucose was determined by high-resolution (13)C NMR spectroscopy. The non-linear progression curves displaying the relative amounts of eight (13)C-glucose isotopologues reflected the contributions of glucose metabolism by glycolytic cycling, the pentose phosphate pathway and anaplerotic reactions involving the citric acid cycle. The pilot study suggests that the experimental setting can be useful in analysing under non-invasive conditions the impact of physiological and pharmacological constraints on glucose turnover in humans.
authors.affiliation: a Lehrstuhl für Biochemie , Technische Universität München , Garching , Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Marsch
authors.forename: Adelbert
authors.initials: A
authors.lastname: Bacher
authors.forename: Christian
authors.initials: C
authors.lastname: Ettenhuber
authors.forename: Tobias
authors.initials: T
authors.lastname: Gräwert
authors.forename: Harald
authors.initials: H
authors.lastname: Mückter
authors.forename: Dietrich
authors.initials: D
authors.lastname: Seidel
authors.forename: Michael
authors.initials: M
authors.lastname: Vogeser
authors.forename: Ralf
authors.initials: R
authors.lastname: Laupitz
authors.forename: Markus
authors.initials: M
authors.lastname: Fischer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Bacher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D002247:Carbon Isotopes / Q000032:analysis; D002952:Citric Acid Cycle; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D010427:Pentose Phosphate Pathway; D010865:Pilot Projects
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes
keywords: carbon-13; clinical study; glucose metabolism; hydrogen-1; isotope application in medicine; isotopologue profiling; man; quantitative NMR spectroscopy; stable isotope tracer techniques