NMR of glycogen in exercise.
Natural-abundance 13C NMR spectroscopy is a non-invasive technique that enables in vivo assessments of muscle and/or liver glycogen concentrations. Over the last several years, 13C NMR has been developed and used to obtain information about human glycogen metabolism with diet and exercise. Since NMR is non-invasive, more data points are available over a specified time course, dramatically improving the time resolution. This improved time resolution has enabled the documentation of subtleties of muscle glycogen re-synthesis following severe glycogen depletion that were not previously observed. Muscle and liver glycogen concentrations have been tracked in several different human populations under conditions that include: (1) muscle glycogen recovery from intense localized exercise with normal insulin and with insulin suppressed; (2) muscle glycogen recovery in an insulin-resistant population; (3) muscle glycogen depletion during prolonged low-intensity exercise; (4) effect of a mixed meal on postprandial muscle and liver glycogen synthesis. The present review focuses on basic 13C NMR and gives results from selected studies.
Price
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TB
Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT 06510, USA. price@boreas.med.yale.edu
Rothman
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DL
Shulman
R G
RG
D015444:Exercise / Q000502:physiology*; D005502:Food; D006003:Glycogen / Q000096:biosynthesis / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D018482:Muscle, Skeletal / Q000378:metabolism*
D007328:Insulin; D006003:Glycogen