A novel 13C NMR method to assess intracellular glucose concentration in muscle, in vivo
Department of Internal Medicine, Yale University School of Medicine and Howard Hughes Medical Institute, New Haven, Connecticut 06520-8020 Intracellular glucose concentration in skeletal muscle of awake rats was determined under conditions of hyperglycemic (10.2 ± 0.6 mM) hyperinsulinemia (~1,200 pM...
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Published in | American journal of physiology: endocrinology and metabolism Vol. 274; no. 2; p. E381 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.02.1998
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Subjects | |
Online Access | Get full text |
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Summary: | Department of Internal Medicine, Yale University School of Medicine
and Howard Hughes Medical Institute, New Haven, Connecticut
06520-8020
Intracellular glucose concentration in skeletal
muscle of awake rats was determined under conditions of hyperglycemic
(10.2 ± 0.6 mM) hyperinsulinemia (~1,200 pM) and hyperglycemic
(20.8 ± 1.5 mM) hypoinsulinemia (<12 pM) by use of
13 C nuclear magnetic resonance
(NMR) spectroscopy during a prime-constant infusion of
[1- 13 C]glucose and
[1- 13 C]mannitol with
either insulin (10 mU · kg 1 · min 1 )
or somatostatin (1.0 µg · kg 1 · min 1 ).
Intracellular glucose was calculated as the difference between the
concentrations of total tissue glucose (calculated from the in vivo
13 C NMR spectrum with mannitol as
an internal concentration standard) and extracellular glucose,
corrected by the ratio of intra- and extracellular water space.
Extracellular concentration was corrected for an interstitial
fluid-to-plasma glucose concentration gradient of 0.83 ± 0.07, determined by open-flow microperfusion. The mean ratio of intra- to
extracellular glucose space, determined from the relative NMR signal
intensities and concentrations of mannitol and total creatine, was 9.2 ± 1.1 (hyperglycemic hyperinsulinemia, n = 10), and 9.0 ± 1.7 (hyperglycemic hypoinsulinemia, n = 7). Mean muscle intracellular glucose concentration was <0.07 mM
under hyperglycemic-hyperinsulinemic conditions
( n = 10) and 0.32 ± 0.06 mM under
hyperglycemic-hypoinsulinemic conditions
( n = 7). This method is noninvasive
and should prove useful for resolving the question of whether glucose
transport or phosphorylation is responsible for the reduced rate of
muscle glycogen synthesis observed in diabetic subjects.
nuclear magnetic resonance spectroscopy |
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Bibliography: | S20 S30 1997075095 |
ISSN: | 0002-9513 0193-1849 2163-5773 1522-1555 |
DOI: | 10.1152/ajpendo.1998.274.2.E381 |