HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 293/6/E1726    most recent 00388.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Fram, R. Y. Articles by Wolfe, R. R. Search for Related Content PubMed PubMed Citation Articles by Fram, R. Y. Articles by Wolfe, R. R.

Recovery of labeled CO₂ from acetate in severely burned children

¹Metabolism Unit, ²Department of Surgery, ³Department of Preventive Medicine and Community Health, University of Texas Medical Branch; and ⁴Shriners Hospital for Children, Galveston, Texas

Submitted 20 June 2007 ; accepted in final form 18 September 2007

The purpose of this study was to determine the fractional recovery rate of labeled CO₂ in the breath of severely burned children. This information is needed to perform tracer studies of substrate oxidation using carbon-labeled fatty acids. Nine children, ages 4–14 yr with massive burns participated in the study. All experiments were performed 7 days post burn after an overnight fast. A primed (60 µmol/kg), constant (2.0 µmol·kg^–1·min^–1) infusion of [1,2-¹³C]acetate was given during a 4-h basal period and during a 4-h hyperinsulinemic euglycemic clamp. A priming dose (150 µmol/kg) of NaH¹³CO₃ was given at the beginning of the study. Breath samples were collected every 10 min during the last 40 min of each period. Indirect calorimetry was performed during the last 30 min of each period. The isotopic enrichment of ¹³CO₂ was determined by isotope ratio-mass spectrometry, and total CO₂ excretion was measured by indirect calorimetry. The fractional recovery of acetate label was 0.89 ± 0.05 and 0.88 ± 0.04 during the basal state and clamp, respectively. We conclude that the fractional recovery of labeled acetate in severely burned children is approximately three times the recovery of a nonburned adult and similar to the value in exercising adults. The high recovery rate reflects the rapid turnover of the TCA cycle in burned children relative to the rate of exchange reactions. Minimal correction of expired CO₂ data is needed in this circumstance to quantify fatty acid oxidation using ¹³C-labeled fatty acids.

acetate correction factor; fatty acid oxidation