Simultaneous determination of the rates of the TCA cycle, glucose utilization, alpha-ketoglutarate/glutamate exchange, and glutamine synthesis in human brain by NMR.

Détails

ID Serval
serval:BIB_518B181E5A2E
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Simultaneous determination of the rates of the TCA cycle, glucose utilization, alpha-ketoglutarate/glutamate exchange, and glutamine synthesis in human brain by NMR.
Périodique
Journal of Cerebral Blood Flow and Metabolism
Auteur(s)
Mason G.F., Gruetter R., Rothman D.L., Behar K.L., Shulman R.G., Novotny E.J.
ISSN
0271-678X (Print)
ISSN-L
0271-678X
Statut éditorial
Publié
Date de publication
1995
Volume
15
Numéro
1
Pages
12-25
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.Publication Status: ppublish
Résumé
13C isotopic tracer data previously obtained by 13C nuclear magnetic resonance in the human brain in vivo were analyzed using a mathematical model to determine metabolic rates in a region of the human neocortex. The tricarboxylic acid (TCA) cycle rate was 0.73 +/- 0.19 mumol min-1 g-1 (mean +/- SD; n = 4). The standard deviation reflects primarily intersubject variation, since individual uncertainties were low. The rate of alpha-ketoglutarate/glutamate exchange was 57 +/- 26 mumol min-1 g-1 (n = 3), which is much greater than the TCA cycle rate; the high rate indicates that alpha-ketoglutarate and glutamate are in rapid exchange and can be treated as a single combined kinetic pool. The rate of synthesis of glutamine from glutamate was 0.47 mumol min-1 g-1 (n = 4), with 95% confidence limits of 0.139 and 3.094 mumol min-1 g-1; individual uncertainties were biased heavily toward high synthesis rates. From the TCA cycle rate the brain oxygen consumption was estimated to be 2.14 +/- 0.48 mumol min-1 g-1 (5.07 +/- 1.14 ml 100 g-1 min-1; n = 4), and the rate of brain glucose consumption was calculated to be 0.37 +/- 0.08 mumol min-1 g-1 (n = 4). The sensitivity of the model to the assumptions made was evaluated, and the calculated values were found to be unchanged as long as the assumptions remained near reported physiological values.
Mots-clé
Brain/metabolism, Carbon Isotopes, Citric Acid Cycle, Glucose/metabolism, Glutamic Acid/metabolism, Glutamine/biosynthesis, Glycolysis, Humans, Ketoglutaric Acids/metabolism, Ketone Bodies/metabolism, Kinetics, Lactates/metabolism, Lactic Acid, Magnetic Resonance Spectroscopy, Mathematics, Models, Biological, Oxygen Consumption, Pyruvate Carboxylase/metabolism, Pyruvates/metabolism, Pyruvic Acid
Pubmed
Web of science
Création de la notice
04/08/2010 16:28
Dernière modification de la notice
03/03/2018 17:11
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