title: Glycolysis versus TCA cycle in the primate brain as measured by combining 18F-FDG PET and 13C-NMR.
abstract: The glycolytic flux (cerebral metabolic rate of glucose CMRglc) and the TCA cycle flux (VTCA) were measured in the same monkeys by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and 13C NMR spectroscopy, respectively. Registration of nuclear magnetic resonance (NMR) and PET data were used for comparison of CMRglc and VTCA in the exact same area of the brain. Both fluxes were in good agreement with literature values (CMRglc=0.23+/-0.03 micromol/g min, VTCA=0.53+/-0.13 micromol/g min). The resulting [CMRglc/VTCA] ratio was 0.46+/-0.12 (n=5, mean+/-s.d.), not significantly different from the 0.5 expected when glucose is the sole fuel that is completely oxidized. Our results provide a cross-validation of both techniques. Comparison of CMRglc with VTCA is in agreement with a metabolic coupling between the TCA cycle and glycolysis under normal physiologic conditions.
authors.affiliation: Commissariat à l'Energie Atomique, Service Hospitalier Frédéric Joliot, Orsay, France.
authors.forename: Fawzi
authors.initials: F
authors.lastname: Boumezbeur
authors.forename: Laurent
authors.initials: L
authors.lastname: Besret
authors.forename: Julien
authors.initials: J
authors.lastname: Valette
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Gregoire
authors.forename: Thierry
authors.initials: T
authors.lastname: Delzescaux
authors.forename: Renaud
authors.initials: R
authors.lastname: Maroy
authors.forename: Françoise
authors.initials: F
authors.lastname: Vaufrey
authors.forename: Philippe
authors.initials: P
authors.lastname: Gervais
authors.forename: Philippe
authors.initials: P
authors.lastname: Hantraye
authors.forename: Gilles
authors.initials: G
authors.lastname: Bloch
authors.forename: Vincent
authors.initials: V
authors.lastname: Lebon
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D002952:Citric Acid Cycle / Q000502:physiology*; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D008251:Macaca; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage* / Q000378:metabolism
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose