Evidence for suppression of hepatic glucose-6-phosphatase with carbohydrate feeding

C. B. Newgard, D. W. Foster, J. McGarry

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

The mechanism by which exogenous glucose stimulates the incorporation of hepatic glucose-6-phosphate into glycogen in fasted rats has not been clearly delineated. We gave glucose intragastrically over a 3.5-h period during which liver glycogen was deposited at linear rates. Simultaneous primed continuous infusion of [2-3H] or [3-3H]glucose established that under these conditions absolute carbon flow through heapatic glucose-6-phosphatase was greatly suppressed. After 1 h, hepatic [UDP-glucose] and [glucose-6-phosphate] had fallen by 50-60% and the former remained low throughout the experiment. By contrast, [glucose-6-phosphate] rebounded to its initial value by 2 h and remained at this level during the subsequent hour. We interpret the data as follows. Exogenous glucose, in addition to acting as a precursor of liver glucose-6-phosphate, causes diversion of the latter away from free glucose formation and into glycogen synthesis. The fall in [UDP-glucose] is in accord with a glucose-induced activation of glycogen synthase, as proposed by Hers (Annu. Rev. Biochem. 1976; 45:167-89.). However, the fall-rise sequence of glucose-6-phosphate concentration constitutes the first direct evidence in vivo for simultaneous inhibition at the level of glucose 6-phosphatase.

Original languageEnglish (US)
Pages (from-to)192-195
Number of pages4
JournalDiabetes
Volume33
Issue number2
StatePublished - 1984

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Glucose-6-Phosphatase
Glucose-6-Phosphate
Carbohydrates
Glucose
Liver
Uridine Diphosphate Glucose
Glycogen
Glycogen Synthase
Liver Glycogen
Carbon

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Internal Medicine

Cite this

Evidence for suppression of hepatic glucose-6-phosphatase with carbohydrate feeding. / Newgard, C. B.; Foster, D. W.; McGarry, J.

In: Diabetes, Vol. 33, No. 2, 1984, p. 192-195.

Research output: Contribution to journalArticle

Newgard, C. B. ; Foster, D. W. ; McGarry, J. / Evidence for suppression of hepatic glucose-6-phosphatase with carbohydrate feeding. In: Diabetes. 1984 ; Vol. 33, No. 2. pp. 192-195.
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