Premium
NMR measurement of brain oxidative metabolism in monkeys using 13 C‐labeled glucose without a 13 C radiofrequency channel
Author(s) -
Boumezbeur Fawzi,
Besret Laurent,
Valette Julien,
Vaufrey Françoise,
Henry PierreGilles,
Slavov Velislav,
Giacomini Eric,
Hantraye Philippe,
Bloch Gilles,
Lebon Vincent
Publication year - 2004
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.20129
Subject(s) - glutamate receptor , chemistry , nuclear magnetic resonance , oxidative metabolism , nuclear magnetic resonance spectroscopy , metabolism , biochemistry , stereochemistry , physics , receptor
We detected glutamate C4 and C3 labeling in the monkey brain during an infusion of [U‐ 13 C 6 ]glucose, using a simple 1 H PRESS sequence without 13 C editing or decoupling. Point‐resolved spectroscopy (PRESS) spectra revealed decreases in 12 C‐bonded protons, and increases in 13 C‐bonded protons of glutamate. To take full advantage of the simultaneous detection of 12 C‐ and 13 C‐bonded protons, we implemented a quantitation procedure to properly measure both glutamate C4 and C3 enrichments. This procedure relies on LCModel analysis with a basis set to account for simultaneous signal changes of protons bound to 12 C and 13 C. Signal changes were mainly attributed to 12 C‐ and 13 C‐bonded protons of glutamate. As a result, we were able to measure the tricarboxylic acid (TCA) cycle flux in a 3.9 cm 3 voxel centered in the monkey brain on a whole‐body 3 Tesla system (V TCA = 0.55 ± 0.04 μmol.g −1 .min −1 , N = 4). This work demonstrates that oxidative metabolism can be quantified in deep structures of the brain on clinical MRI systems, without the need for a 13 C radiofrequency (RF) channel. Magn Reson Med 52:33–40, 2004. © 2004 Wiley‐Liss, Inc.