Effect of hypoglycemia on brain glycogen metabolism in vivo.

Details

Serval ID
serval:BIB_A4A66BAD48A3
Type
Article: article from journal or magazin.
Collection
Publications
Title
Effect of hypoglycemia on brain glycogen metabolism in vivo.
Journal
Journal of Neuroscience Research
Author(s)
Choi I.Y., Seaquist E.R., Gruetter R.
ISSN
0360-4012 (Print)
ISSN-L
0360-4012
Publication state
Published
Issued date
04/2003
Volume
72
Number
1
Pages
25-32
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.Publication Status: ppublish. PDF type: Research Article
Abstract
The brain contains a small but significant amount of glycogen, which has long been considered to play an insignificant role in the brain. In this study, brain glycogen metabolism was measured using (13)C NMR spectroscopy at 9.4 T. Brain glycogen metabolism was modulated by hyperinsulinemia resulting in a net accumulation. The role of glycogen in maintaining brain function is unknown; one possibility is that it may serve as an endogenous glucose reservoir to protect the brain against severe hypoglycemia. To address this possibility, rats were subjected to insulin-induced moderate hypoglycemia and when the level of brain glucose approached zero, brain glycogen content began to decrease gradually, demonstrating utilization of this glucose reservoir. The brain glycogen signal never became undetectable, however, even during 2 hr of hypoglycemia. When plasma and brain glucose concentrations were restored, glycogen increased and the concentration exceeded the pre-hypoglycemic level by several-fold. The data suggest that brain glycogen can provide fuel for extended periods of time when glucose supply is inadequate. Furthermore, brain glycogen can rebound (super-compensate) after a single episode of hypoglycemia. We postulate that brain glycogen serves as an energy store during hypoglycemia and that it may participate in the creation of reduced physiological responses to hypoglycemia that are involved in a symptom often observed in patients with diabetes, hypoglycemia unawareness.
Keywords
Animals, Brain/drug effects, Brain/metabolism, Glycogen/metabolism, Hypoglycemia/chemically induced, Hypoglycemia/metabolism, Insulin/pharmacology, Magnetic Resonance Spectroscopy/methods, Male, Rats, Rats, Sprague-Dawley
Pubmed
Web of science
Create date
04/08/2010 15:28
Last modification date
20/08/2019 15:10
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