No full text
Article (Scientific journals)
Endogenous substrate oxidation during exercise and variations in breath 13CO2/12CO2.
Gautier, J. F.; Pirnay, Freddy; Jandrain, Bernard et al.
1993In Journal of Applied Physiology, 74 (1), p. 133-8
Peer Reviewed verified by ORBi
 

Files


Full Text
No document available.

Send to



Details



Keywords :
Adult; Breath Tests; Calorimetry; Carbon Dioxide/metabolism; Carbon Isotopes; Energy Metabolism/physiology; Exercise/physiology; Humans; Male; Mass Spectrometry; Oxidation-Reduction
Abstract :
[en] This study attempted to induce a major shift in the utilization of endogenous substrates during exercise in men by the use of a potent inhibitor of adipose tissue lipolysis, Acipimox, and to see to what extent this affects the 13C/12C ratio in expired air CO2. Six healthy volunteers exercised for 3 h on a treadmill at approximately 45% of their maximum O2 uptake, 75 min after having ingested either a placebo or 250 mg Acipimox. The rise in plasma free fatty acids and glycerol was almost totally prevented by Acipimox, and no significant rise in the utilization of lipids, evaluated by indirect calorimetry, was observed. Total carbohydrate oxidation averaged 128 +/- 17 (placebo) and 182 +/- 21 g/3 h (Acipimox). Conversely, total lipid oxidation was 84 +/- 5 (placebo) and 57 +/- 6 g/3 h (Acipimox; P < 0.01). Under placebo, changes in expired air CO2 delta 13C were minimal, with only a 0.49/1000 significant rise at 30 min. In contrast, under Acipimox, the rise in expired air CO2 delta 13C averaged 1/1000 and was significant throughout the 3-h exercise bout; in these conditions calculation of a "pseudooxidation" of an exogenous sugar naturally or artificially enriched in 13C, but not ingested, would have given an erroneous value of 19.8 +/- 2.6 g/3 h. Thus under conditions of extreme changes in endogenous substrate utilization, an appropriate control experiment is mandatory when studying exogenous substrate oxidation by 13C-labeled substrates and isotope-ratio mass spectrometry measurements on expired air CO2.
Disciplines :
Endocrinology, metabolism & nutrition
Author, co-author :
Gautier, J. F.
Pirnay, Freddy ;  Centre Hospitalier Universitaire de Liège - CHU > Pneumologie-Allergologie
Jandrain, Bernard ;  Centre Hospitalier Universitaire de Liège - CHU > Diabétologie,nutrition, maladies métaboliques
Lacroix, M.
Mosora, F.
Scheen, André  ;  Université de Liège - ULiège > Département des sciences cliniques > Diabétologie, nutrition et maladie métaboliques - Médecine interne générale
Lefebvre, Pierre ;  Centre Hospitalier Universitaire de Liège - CHU > Diabétologie,nutrition, maladies métaboliques
Language :
English
Title :
Endogenous substrate oxidation during exercise and variations in breath 13CO2/12CO2.
Publication date :
1993
Journal title :
Journal of Applied Physiology
ISSN :
8750-7587
eISSN :
1522-1601
Publisher :
American Physiological Society, Bethesda, United States - Maryland
Volume :
74
Issue :
1
Pages :
133-8
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 05 June 2009

Statistics


Number of views
77 (1 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
15
Scopus citations®
without self-citations
13
OpenCitations
 
15

Bibliography


Similar publications



Contact ORBi