Table of Contents Author Guidelines Submit a Manuscript
BioMed Research International
Volume 2013, Article ID 638085, 7 pages
http://dx.doi.org/10.1155/2013/638085
Methodology Report

Noninvasive Measurement of Murine Hepatic Acetyl-CoA 13C-Enrichment Following Overnight Feeding with 13C-Enriched Fructose and Glucose

1Center for Neurosciences and Cell Biology, Department of Zoology, University of Coimbra, Coimbra 3004-517, Portugal
2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
3Department of Chemistry, University of Coimbra, Coimbra 3004-535, Portugal
4APDP-Portuguese Diabetes Association, Lisbon 1250-261, Portugal

Received 2 April 2013; Accepted 14 May 2013

Academic Editor: Yutaka Yata

Copyright © 2013 Filipa Carvalho et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The 13C-isotopomer enrichment of hepatic cytosolic acetyl-CoA of overnight-fed mice whose drinking water was supplemented with [U-13C]fructose, and [1-13C]glucose and p-amino benzoic acid (PABA) was quantified by 13C NMR analysis of urinary N-acetyl-PABA. Four mice were given normal chow plus drinking water supplemented with 5% [1-13C]glucose, 2.5% [U-13C]fructose, and 2.5% fructose (Solution 1) overnight. Four were given chow and water containing 17.5% [1-13C]glucose, 8.75% [U-13C]fructose and 8.75% fructose (Solution 2). PABA (0.25%) was present in both studies. Urinary N-acetyl-PABA was analyzed by 13C NMR. In addition to [2-13C]- and [1,2-13C]acetyl isotopomers from catabolism of [U-13C]fructose and [1-13C]glucose to acetyl-CoA, [1-13C]acetyl was also found indicating pyruvate recycling activity. This precluded precise estimates of [1-13C]glucose contribution to acetyl-CoA while that of [U-13C]fructose was unaffected. The fructose contribution to acetyl-CoA from Solutions 1 and 2 was 4.0 ± 0.4% and 10.6 ± 0.6%, respectively, indicating that it contributed to a minor fraction of lipogenic acetyl-CoA under these conditions.