AJP - Cell Physiology, Vol 264, Issue 3 C727-C733, Copyright © 1993 by American Physiological Society

ARTICLES

Effects of exercise training on skeletal muscle glucose uptake and transport

G. J. Etgen Jr, J. T. Brozinick Jr, H. Y. Kang and J. L. Ivy
Department of Kinesiology, University of Texas, Austin 78712.

Exercise training increases the concentration of GLUT-4 protein in skeletal muscle that is associated with an increase in maximal insulin-stimulated glucose transport. The purpose of this study was to determine whether exercise training results in a long-lasting increase in insulin-stimulated glucose transport in rat skeletal muscle. Glucose uptake and skeletal muscle 3-O-methyl-D-glucose (3-MG) transport were determined during hindlimb perfusion in the presence of a maximally stimulating concentration of insulin (10 mU/ml). Hindlimb glucose uptake was approximately 29% above sedentary (Sed) levels in rats examined within 24 h (24H) of their last exercise session. However, when rats were examined 48 h (48H) after their last exercise session, hindlimb glucose uptake was not different from Sed levels. Maximal 3-MG transport was enhanced, above Sed levels, in red (RG; 72% increase) and white (WG; 44% increase) gastrocnemius and plantaris (Plan; 67% increase) muscles, but not soleus (Sol), of 24H rats. GLUT-4 protein content was significantly elevated in those muscles that exhibited enhanced 3-MG transport in 24H rats. GLUT-4 protein content was also elevated in RG, WG, and Plan of 48H rats and was not different from 24H rats. Despite the elevated GLUT-4 protein content, 3-MG transport in 48H rats was only slightly, although statistically not significantly, higher than in Sed rats. These results provide evidence that exercise training does not result in a persistent increase in skeletal muscle glucose uptake or transport, despite an increase in GLUT-4 protein content.

This article has been cited by other articles:

				E. B. Arias, L. E. Gosselin, and G. D. Cartee Exercise Training Eliminates Age-Related Differences in Skeletal Muscle Insulin Receptor and IRS-1 Abundance in Rats J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2001; 56(10): B449 - 455. [Abstract] [Full Text] [PDF]

				S. Kristiansen, J. Gade, J. F. P. Wojtaszewski, B. Kiens, and E. A. Richter Glucose uptake is increased in trained vs. untrained muscle during heavy exercise J Appl Physiol, September 1, 2000; 89(3): 1151 - 1158. [Abstract] [Full Text] [PDF]

				T. H. Reynolds IV, J. T. Brozinick Jr., L. M. Larkin, and S. W. Cushman Transient enhancement of GLUT-4 levels in rat epitrochlearis muscle after exercise training J Appl Physiol, June 1, 2000; 88(6): 2240 - 2245. [Abstract] [Full Text] [PDF]

				L. P. Turcotte, J. R. Swenberger, M. Z. Tucker, and A. J. Yee Training-induced elevation in FABPPM is associated with increased palmitate use in contracting muscle J Appl Physiol, July 1, 1999; 87(1): 285 - 293. [Abstract] [Full Text] [PDF]

				P. E. Willis, S. G. Chadan, V. Baracos, and W. S. Parkhouse Restoration of insulin-like growth factor I action in skeletal muscle of old mice Am J Physiol Endocrinol Metab, September 1, 1998; 275(3): E525 - E530. [Abstract] [Full Text] [PDF]

				H. H. Host, P. A. Hansen, L. A. Nolte, M. M. Chen, and J. O. Holloszy Rapid reversal of adaptive increases in muscle GLUT-4 and glucose transport capacity after training cessation J Appl Physiol, March 1, 1998; 84(3): 798 - 802. [Abstract] [Full Text] [PDF]

				A. L. Castle, C.-H. Kuo, and J. L. Ivy Amylin influences insulin-stimulated glucose metabolism by two independent mechanisms Am J Physiol Endocrinol Metab, January 1, 1998; 274(1): E6 - E12. [Abstract] [Full Text] [PDF]

				E. A. Richter, P. Jensen, B. Kiens, and S. Kristiansen Sarcolemmal glucose transport and GLUT-4 translocation during exercise are diminished by endurance training Am J Physiol Endocrinol Metab, January 1, 1998; 274(1): E89 - E95. [Abstract] [Full Text] [PDF]