Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 86: 2077-2089, 1999;
8750-7587/99 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bertocci, L. A.
Right arrow Articles by Lujan, B. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bertocci, L. A.
Right arrow Articles by Lujan, B. F.
Vol. 86, Issue 6, 2077-2089, June 1999

Incorporation and utilization of [3-13C]lactate and [1,2-13C]acetate by rat skeletal muscle

Loren A. Bertocci and Barbara F. Lujan

Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, Dallas 75231; and Department of Radiology and Program in Advanced Radiological Sciences, University of Texas Southwestern Medical Center, Dallas, Texas 75235-9085

Skeletal muscle can utilize many different substrates, and traditional methodologies allow only indirect discrimination between oxidative and nonoxidative uptake of substrate, possibly with contamination by metabolism of other internal organs. Our goal was to apply 1H- and 13C-nuclear magnetic resonance spectroscopy to monitor the patterns of [3-13C]lactate and [1,2-13C]acetate (model of simple carbohydrates and fats, respectively) utilization in resting vs. contracting muscle extracts of the isolated perfused rat hindquarter. Total metabolite concentrations were measured by using NADH-linked fluorometric assays. Fractional oxidation of [3-13C]lactate was unchanged by contraction despite vascular endogenous lactate accumulation. Although label accumulated in several citric acid cycle (CAC) intermediates, contraction did not increase the concentration of CAC intermediates in any muscle extracts. We conclude that 1) the isolated rat hindquarter is a viable, well-controlled model for measuring skeletal muscle 13C-labeled substrate utilization; 2) lactate is readily oxidized even during contractile activity; 3) entry and exit from the CAC, via oxidative and nonoxidative pathways, is a component of normal muscle metabolism and function; and 4) there are possible differences between gastrocnemius and soleus muscles in utilization of nonoxidative pathways.

citric acid cycle; glycolysis; gastrocnemius; soleus; isolated perfused rat hindquarter; carbon-13-nuclear magnetic resonance spectroscopy; hydrogen-1-nuclear magnetic resonance spectroscopy; muscle metabolism; anaplerosis; lactate shuttle


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
T. Hashimoto, R. Hussien, and G. A. Brooks
Colocalization of MCT1, CD147, and LDH in mitochondrial inner membrane of L6 muscle cells: evidence of a mitochondrial lactate oxidation complex
Am J Physiol Endocrinol Metab, June 1, 2006; 290(6): E1237 - E1244.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
K. M. Kelley, J. J. Hamann, C. Navarre, and L. B. Gladden
Lactate metabolism in resting and contracting canine skeletal muscle with elevated lactate concentration
J Appl Physiol, September 1, 2002; 93(3): 865 - 872.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
B. C. Bergman, E. E. Wolfel, G. E. Butterfield, G. D. Lopaschuk, G. A. Casazza, M. A. Horning, and G. A. Brooks
Active muscle and whole body lactate kinetics after endurance training in men
J Appl Physiol, November 1, 1999; 87(5): 1684 - 1696.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
G. A. Brooks, M. A. Brown, C. E. Butz, J. P. Sicurello, and H. Dubouchaud
Cardiac and skeletal muscle mitochondria have a monocarboxylate transporter MCT1
J Appl Physiol, November 1, 1999; 87(5): 1713 - 1718.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online