AJP - Endo Information on EB 2010
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 280: E598-E607, 2001;
0193-1849/01 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (12)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chase, J. R.
Right arrow Articles by Shulman, R. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chase, J. R.
Right arrow Articles by Shulman, R. G.
Vol. 280, Issue 4, E598-E607, April 2001

Flux control in the rat gastrocnemius glycogen synthesis pathway by in vivo 13C/31P NMR spectroscopy

J. R. Chase1, D. L. Rothman2, and R. G. Shulman1

Departments of 1 Molecular Biophysics and Biochemistry and 2 Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510

To determine the relative contributions of glucose transport/hexokinase, glycogen synthase (GSase), and glycolysis to the control of insulin-stimulated muscle glycogen synthesis, we combined 13C and 31P NMR to quantitate the glycogen synthesis rate and glucose 6-phosphate (G-6-P) levels in rat (Sprague-Dawley) gastrocnemius muscle during hyperinsulinemia at euglycemic (E) and hyperglycemic (H) glucose concentrations under thiopental anesthesia. Flux control was calculated using metabolic control analysis. The combined control coefficient of glucose transport/hexokinase (GT/Hk) for glycogen synthesis was 1.1 ± 0.03 (direct measure) and 1.14-1.16 (calculated for a range of glycolytic fluxes), whereas the control coefficient for GSase was much lower (0.011-0.448). We also observed that the increase in in vivo [G-6-P] from E to H (0.22 ± 0.03 to 0.40 ± 0.03 mM) effects a supralinear increase in the in vitro velocity of GSase, from 14.6 to 26.1 mU · kg-1 · min-1 (1.8-fold). All measurements suggest that the majority of the flux control of muscle glycogen synthesis is at the GT/Hk step.

metabolic control analysis; glucose transport; hyperglycemia; hyperinsulinemia


This article has been cited by other articles:


Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
G. Raja, L. Brau, T. N. Palmer, and P. A. Fournier
Fiber-specific responses of muscle glycogen repletion in fasted rats physically active during recovery from high-intensity physical exertion
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2008; 295(2): R633 - R641.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
J. Frolow and C. L. Milligan
Hormonal regulation of glycogen metabolism in white muscle slices from rainbow trout (Oncorhynchus mykiss Walbaum)
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2004; 287(6): R1344 - R1353.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
J. R. A. Schafer, D. A. Fell, D. Rothman, and R. G. Shulman
Protein phosphorylation can regulate metabolite concentrations rather than control flux: The example of glycogen synthase
PNAS, February 10, 2004; 101(6): 1485 - 1490.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online