Human brain glycogen content and metabolism: implications on its role in brain energy metabolism.

Details

Serval ID
serval:BIB_9E6B37C01AA8
Type
Article: article from journal or magazin.
Collection
Publications
Title
Human brain glycogen content and metabolism: implications on its role in brain energy metabolism.
Journal
American Journal of Physiology. Endocrinology and Metabolism
Author(s)
Oz G., Seaquist E.R., Kumar A., Criego A.B., Benedict L.E., Rao J.P., Henry P.G., Van De Moortele P.F., Gruetter R.
ISSN
0193-1849 (Print)
ISSN-L
0193-1849
Publication state
Published
Issued date
2007
Volume
292
Number
3
Pages
E946-E951
Language
english
Notes
Publication types: Clinical Trial ; Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Abstract
The adult brain relies on glucose for its energy needs and stores it in the form of glycogen, primarily in astrocytes. Animal and culture studies indicate that brain glycogen may support neuronal function when the glucose supply from the blood is inadequate and/or during neuronal activation. However, the concentration of glycogen and rates of its metabolism in the human brain are unknown. We used in vivo localized 13C-NMR spectroscopy to measure glycogen content and turnover in the human brain. Nine healthy volunteers received intravenous infusions of [1-(13)C]glucose for durations ranging from 6 to 50 h, and brain glycogen labeling and washout were measured in the occipital lobe for up to 84 h. The labeling kinetics suggest that turnover is the main mechanism of label incorporation into brain glycogen. Upon fitting a model of glycogen metabolism to the time courses of newly synthesized glycogen, human brain glycogen content was estimated at approximately 3.5 micromol/g, i.e., three- to fourfold higher than free glucose at euglycemia. Turnover of bulk brain glycogen occurred at a rate of 0.16 micromol.g-1.h-1, implying that complete turnover requires 3-5 days. Twenty minutes of visual stimulation (n=5) did not result in detectable glycogen utilization in the visual cortex, as judged from similar [13C]glycogen levels before and after stimulation. We conclude that the brain stores a substantial amount of glycogen relative to free glucose and metabolizes this store very slowly under normal physiology.
Keywords
Adult, Brain/metabolism, Brain Chemistry, Energy Metabolism, Female, Glucose/administration & dosage, Glucose/pharmacokinetics, Glycogen/analysis, Glycogen/metabolism, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Models, Theoretical, Photic Stimulation
Pubmed
Web of science
Create date
04/08/2010 15:28
Last modification date
20/08/2019 15:04
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