Document Detail


Human brain glycogen metabolism during and after hypoglycemia.
MedLine Citation:
PMID:  19502412     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: We tested the hypotheses that human brain glycogen is mobilized during hypoglycemia and its content increases above normal levels ("supercompensates") after hypoglycemia. RESEARCH DESIGN AND METHODS: We utilized in vivo (13)C nuclear magnetic resonance spectroscopy in conjunction with intravenous infusions of [(13)C]glucose in healthy volunteers to measure brain glycogen metabolism during and after euglycemic and hypoglycemic clamps. RESULTS: After an overnight intravenous infusion of 99% enriched [1-(13)C]glucose to prelabel glycogen, the rate of label wash-out from [1-(13)C]glycogen was higher (0.12 +/- 0.05 vs. 0.03 +/- 0.06 micromol x g(-1) x h(-1), means +/- SD, P < 0.02, n = 5) during a 2-h hyperinsulinemic-hypoglycemic clamp (glucose concentration 57.2 +/- 9.7 mg/dl) than during a hyperinsulinemic-euglycemic clamp (95.3 +/- 3.3 mg/dl), indicating mobilization of glucose units from glycogen during moderate hypoglycemia. Five additional healthy volunteers received intravenous 25-50% enriched [1-(13)C]glucose over 22-54 h after undergoing hyperinsulinemic-euglycemic (glucose concentration 92.4 +/- 2.3 mg/dl) and hyperinsulinemic-hypoglycemic (52.9 +/- 4.8 mg/dl) clamps separated by at least 1 month. Levels of newly synthesized glycogen measured from 4 to 80 h were higher after hypoglycemia than after euglycemia (P <or= 0.01 for each subject), indicating increased brain glycogen synthesis after moderate hypoglycemia. CONCLUSIONS: These data indicate that brain glycogen supports energy metabolism when glucose supply from the blood is inadequate and that its levels rebound to levels higher than normal after a single episode of moderate hypoglycemia in humans.
Authors:
Gülin Oz; Anjali Kumar; Jyothi P Rao; Christopher T Kodl; Lisa Chow; Lynn E Eberly; Elizabeth R Seaquist
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, N.I.H., Extramural     Date:  2009-06-05
Journal Detail:
Title:  Diabetes     Volume:  58     ISSN:  1939-327X     ISO Abbreviation:  Diabetes     Publication Date:  2009 Sep 
Date Detail:
Created Date:  2009-09-01     Completed Date:  2009-09-30     Revised Date:  2010-09-02    
Medline Journal Info:
Nlm Unique ID:  0372763     Medline TA:  Diabetes     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1978-85     Citation Subset:  AIM; IM    
Affiliation:
Center for MR Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA. gulin@cmrr.umn.edu
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology
Adult
Blood Glucose / metabolism
Brain / metabolism*
Carbon Isotopes / diagnostic use
Energy Metabolism / physiology*
Female
Glucose / administration & dosage
Glucose Clamp Technique
Glycogen / biosynthesis*,  metabolism*
Humans
Hyperinsulinism / metabolism
Hypoglycemia / metabolism*
Infusions, Intravenous
Magnetic Resonance Spectroscopy
Male
Models, Biological
Young Adult
Grant Support
ID/Acronym/Agency:
M01RR00400/RR/NCRR NIH HHS; P30NS057091/NS/NINDS NIH HHS; P41RR008079/RR/NCRR NIH HHS; R01 NS035192/NS/NINDS NIH HHS
Chemical
Reg. No./Substance:
0/Blood Glucose; 0/Carbon Isotopes; 50-99-7/Glucose; 9005-79-2/Glycogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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