AJP - Endo AJP: Cell Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 277: E505-E512, 1999;
0193-1849/99 $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 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 Google Scholar
Google Scholar
Right arrow Articles by Jucker, B. M.
Right arrow Articles by Shulman, G. I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jucker, B. M.
Right arrow Articles by Shulman, G. I.
Vol. 277, Issue 3, E505-E512, September 1999

EPILOGUE
Metabolic control analysis of insulin-stimulated glucose disposal in rat skeletal muscle

Beat M. Jucker1, Nicole Barucci1, and Gerald I. Shulman2

1 Department of Internal Medicine and the 2 Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06520-8020

Metabolic control analysis was used to calculate the distributed control of insulin-stimulated skeletal muscle glucose disposal in awake rats. Three separate hyperinsulinemic infusion protocols were performed: 1) protocol I was a euglycemic (~6 mM)-hyperinsulinemic (10 mU · kg-1 · min-1) clamp, 2) protocol II was a hyperglycemic (~11 mM)-hyperinsulinemic (10 mU · kg-1 · min-1) clamp, and 3) protocol III was a euglycemic (~6 mM)-hyperinsulinemic (10 mU · kg-1 · min-1)-lipid/heparin (increased plasma free fatty acid) clamp. [1-13C]glucose was administered in all three protocols for a 3-h period, during which time [1-13C]glucose label incorporation into [1-13C]glycogen, [3-13C]lactate, and [3-13C]alanine was detected in the hindlimb of awake rats via 13C-NMR. Combined steady-state and kinetic data were used to calculate rates of glycogen synthesis and glycolysis. Additionally, glucose 6-phosphate (G-6-P) was measured in the hindlimb muscles with the use of in vivo 31P-NMR during the three infusion protocols. The clamped glucose infusion rates were 31.6 ± 2.9, 49.7 ± 1.0, and 24.0 ± 1.5 mg · kg-1 · min-1 at 120 min in protocols I-III, respectively. Rates of glycolysis were 62.1 ± 10.3, 71.6 ± 11.8, and 19.5 ± 3.6 nmol · g-1 · min-1 and rates of glycogen synthesis were 125 ± 15, 224 ± 23, and 104 ± 17 nmol · g-1 · min-1 in protocols I-III, respectively. Insulin-stimulated G-6-P concentrations were 217 ± 8, 265 ± 12, and 251 ± 9 nmol/g in protocols I-III, respectively. A top-down approach to metabolic control analysis was used to calculate the distributed control among glucose transport/phosphorylation [GLUT-4/hexokinase (HK)], glycogen synthesis, and glycolysis from the metabolic flux and G-6-P data. The calculated values for the control coefficients (C) of these three metabolic steps (CJGLUT-4/HK = 0.55 ± 0.10, CJglycogen syn = 0.30 ± 0.06, and CJglycolysis = 0.15 ± 0.02; where J is glucose disposal flux, and glycogen syn is glycogen synthesis) indicate that there is shared control of glucose disposal and that glucose transport/phosphorylation is responsible for the majority of control of insulin-stimulated glucose disposal in skeletal muscle.

nuclear magnetic resonance; flux control; glycogen synthesis; glycolysis; glucose 6-phosphate


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. Endocrinol. Metab.Home page
J. R. Chase, D. L. Rothman, and R. G. Shulman
Flux control in the rat gastrocnemius glycogen synthesis pathway by in vivo 13C/31P NMR spectroscopy
Am J Physiol Endocrinol Metab, April 1, 2001; 280(4): E598 - E607.
[Abstract] [Full Text] [PDF]

Home page
 J. Nutr.Home page
H. K. Ortmeyer
In Vivo Insulin Regulation of Skeletal Muscle Glycogen Synthase in Calorie-Restricted and in Ad Libitum-Fed Rhesus Monkeys
J. Nutr., March 1, 2001; 131(3): 907S - 912.
[Abstract] [Full Text]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
G. R. Steinberg and D. J. Dyck
Development of leptin resistance in rat soleus muscle in response to high-fat diets
Am J Physiol Endocrinol Metab, December 1, 2000; 279(6): E1374 - E1382.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
I. Azpiazu, J. Manchester, A. V. Skurat, P. J. Roach, and J. C. Lawrence Jr.
Control of glycogen synthesis is shared between glucose transport and glycogen synthase in skeletal muscle fibers
Am J Physiol Endocrinol Metab, February 1, 2000; 278(2): E234 - E243.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
S. Aiston, L. Hampson, A. M. Gomez-Foix, J. J. Guinovart, and L. Agius
Hepatic Glycogen Synthesis Is Highly Sensitive to Phosphorylase Activity. EVIDENCE FROM METABOLIC CONTROL ANALYSIS
J. Biol. Chem., June 22, 2001; 276(26): 23858 - 23866.
[Abstract] [Full Text] [PDF]


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