Tricarboxylic acid cycle of glia in the in vivo human brain

✍ Scribed by S. Blüml; A. Moreno-Torres; F. Shic; C.-H. Nguy; B. D. Ross

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 191 KB
• Volume: 15
• Category: Article
• ISSN: 0952-3480
• DOI: 10.1002/nbm.725

✦ Synopsis

Abstract

In the brain, acetate is exclusively oxidized by glia. To determine the contribution of glial metabolism to the tricarboxylic acid cycle (TCA), 1‐^13^C‐acetate was infused in six studies in three normal adult subjects and ­one epileptic receiving valproic acid for seizure control. Ten grams of 99% 1‐^13^C labeled acetate were infused intravenously as a 3.3% w/v solution over 60 min, during which in vivo ^13^C MR spectra of the brain were acquired. As expected, ^13^C label rapidly enriched cerebral bicarbonate, glutamate and glutamine C~5~. The mean rate of acetate oxidation calculated from steady‐state ^13^C enrichment of bicarbonate in fasted normal subjects was 0.13 ± 0.03 µmol/g/min (n = 4), approximately 20% of the total cerebral TCA cycle rate. Copyright © 2002 John Wiley & Sons, Ltd.