Detection of [1,6-13C2]-glucose metabolism in rat brain by in vivo 1H-[13C]-NMR spectroscopy

✍ Scribed by Robin A. de Graaf; Peter B. Brown; Graeme F. Mason; Douglas L. Rothman; Kevin L. Behar

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 339 KB
• Volume: 49
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.10348

✦ Synopsis

Abstract

Localized, water‐suppressed ^1^H‐[^13^C]‐NMR spectroscopy was used to detect ^13^C‐label accumulation in cerebral metabolites following the intravenous infusion of [1,6‐^13^C~2~]‐glucose (Glc). The ^1^H‐[^13^C]‐NMR method, based on adiabatic RF pulses, 3D image‐selected in vivo spectroscopy (ISIS) localization, and optimal shimming, yielded high‐quality ^1^H‐[^13^C]‐NMR spectra with optimal NMR sensitivity. As a result, the ^13^C labeling of [4‐^13^C]‐glutamate (Glu) and [4‐^13^C]‐glutamine (Gln) could be detected from relatively small volumes (100 μL) with a high temporal resolution. The formation of [n‐^13^C]‐Glu, [n‐^13^C]‐Gln (n = 2 or 3), [2‐^13^C]‐aspartate (Asp), [3‐^13^C]‐Asp, [3‐^13^C]‐alanine (Ala), and [3‐^13^C]‐lactate (Lac) was also observed to be reproducible. The ^13^C‐label incorporation curves of [4‐^13^C]‐Glu and [4‐^13^C]‐Gln provided direct information on metabolic pathways. Using a two‐compartment metabolic model, the tricarboxylic acid (TCA) cycle flux was determined as 0.52 ± 0.04 μmol/min/g, while the glutamatergic neurotransmitter flux equaled 0.25 ± 0.05 μmol/min/g, in good correspondence with previously determined values. Magn Reson Med 49:37–46, 2003. © 2003 Wiley‐Liss, Inc.