Simplified (13)C metabolic modeling for simplified measurements of cerebral TCA cycle rate in vivo.
(13)C NMR spectroscopy is a unique tool to measure the cerebral tricarboxylic acid (TCA) cycle rate in vivo. The measurement relies on metabolic modeling of glutamate C3 and C4 enrichment time courses during a (13)C-glucose intravenous infusion. Usual metabolic models require the plasma glucose and (13)C-glucose time courses as input functions, as well as the knowledge of Michaelis-Menten kinetics parameters governing passage through the blood-brain barrier. It is shown in the present work that, when using an infusion protocol yielding a rapidly stable plasma glucose fractional enrichment, metabolic modeling can be simplified in such a manner that this additional information on input function and glucose transport is no longer required, significantly simplifying the measurement of cerebral TCA cycle rate in vivo.
Valette
Julien
J
CEA-NeuroSpin, Saclay, France. julien.valette@cea.fr
Boumezbeur
Fawzi
F
Hantraye
Philippe
P
Lebon
Vincent
V
D000465:Algorithms; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002247:Carbon Isotopes / Q000493:pharmacokinetics; D002952:Citric Acid Cycle / Q000502:physiology*; D003198:Computer Simulation; D005947:Glucose / Q000378:metabolism*; D000882:Haplorhini; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008959:Models, Neurological
D002247:Carbon Isotopes; D005947:Glucose