Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 88: 1777-1790, 2000;
8750-7587/00 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
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 ISI 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 ISI Web of Science (7)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Geor, R. J.
Right arrow Articles by Sams, R. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Geor, R. J.
Right arrow Articles by Sams, R. A.
Vol. 88, Issue 5, 1777-1790, May 2000

Epinephrine inhibits exogenous glucose utilization in exercising horses

Raymond J. Geor, Kenneth W. Hinchcliff, Laura Jill McCutcheon, and Richard A. Sams

Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio 43210

This study examined the effects of preexercise glucose administration, with and without epinephrine infusion, on carbohydrate metabolism in horses during exercise. Six horses completed 60 min of treadmill exercise at 55 ± 1% maximum O2 uptake 1) 1 h after oral administration of glucose (2 g/kg; G trial); 2) 1 h after oral glucose and with an intravenous infusion of epinephrine (0.2 µmol · kg-1 · min-1; GE trial) during exercise, and 3) 1 h after water only (F trial). Glucose administration (G and GE) caused hyperinsulinemia and hyperglycemia (~8 mM). In GE, plasma epinephrine concentrations were three- to fourfold higher than in the other trials. Compared with F, the glucose rate of appearance was ~50% and ~33% higher in G and GE, respectively, during exercise. The glucose rate of disappearance was ~100% higher in G than in F, but epinephrine infusion completely inhibited the increase in glucose uptake associated with glucose administration. Muscle glycogen utilization was higher in GE [349 ± 44 mmol/kg dry muscle (dm)] than in F (218 ± 28 mmol/kg dm) and G (201 ± 35 mmol/kg dm). We conclude that 1) preexercise glucose augments utilization of plasma glucose in horses during moderate-intensity exercise but does not alter muscle glycogen usage and 2) increased circulating epinephrine inhibits the increase in glucose rate of disappearance associated with preexercise glucose administration and increases reliance on muscle glycogen for energy transduction.

stable isotopes; glucose kinetics; catecholamines; muscle glycogen; insulin


This article has been cited by other articles:


Home page
 J. Nutr.Home page
K. H. Treiber, R. J. Geor, R. C. Boston, T. M. Hess, P. A. Harris, and D. S. Kronfeld
Dietary Energy Source Affects Glucose Kinetics in Trained Arabian Geldings at Rest and during Endurance Exercise
J. Nutr., May 1, 2008; 138(5): 964 - 970.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
E. Jose-Cunilleras, K. W. Hinchcliff, R. A. Sams, S. T. Devor, and J. K. Linderman
Glycemic index of a meal fed before exercise alters substrate use and glucose flux in exercising horses
J Appl Physiol, January 1, 2002; 92(1): 117 - 128.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
S. D. R. Galloway, S. A. Wootton, J. L. Murphy, and R. J. Maughan
Exogenous carbohydrate oxidation from drinks ingested during prolonged exercise in a cold environment in humans
J Appl Physiol, August 1, 2001; 91(2): 654 - 660.
[Abstract] [Full Text] [PDF]


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