|
|
||||||||
Journal of Applied Physiology, Vol 67, Issue 5 1807-1813, Copyright © 1989 by American Physiological Society
ARTICLES |
C. E. Torgan, J. T. Brozinick Jr, G. M. Kastello and J. L. Ivy
Department of Kinesiology, University of Texas at Austin 78712.
The purposes of the present study were to characterize the histochemical and enzymatic profiles of various hindlimb skeletal muscles, as well as to determine maximal O2 consumption (VO2max) and respiratory exchange ratios (R) during steady-state exercise in the obese Zucker rat. The changes that occurred in these parameters in response to a 6-wk training program were then assessed. Obese rats were randomly assigned to a sedentary or training group. Lean littermates served as a second control. Training consisted of treadmill running at 18 m/min up an 8% grade, 1.5 h/day, 5 day/wk for 6 wk. During week 6, VO2max and R during a steady-state run (74% max) were determined. After 2 days of inactivity, hindlimb muscles were excised, stained for fiber type and capillaries, and assayed for hexokinase, citrate synthase, cytochrome oxidase, and beta-hydroxyacetyl-CoA dehydrogenase. The obese sedentary rats demonstrated greater oxidative enzyme activities per gram of muscle tissue than their lean littermates, greater R values during submaximal exercise of the same relative intensity, and greater absolute VO2max values. Training resulted in a 20-56% increase in oxidative enzymes, a 10% increase in VO2max, and an increase in capillary density in the soleus and plantaris. There was no alteration in R values during exercise at 74% VO2max or in fiber type composition in response to exercise training. Results suggest that the muscle of the obese Zucker rat manifests a greater oxidative capacity than the muscle of its lean littermates. The apparent inability of the obese rat to increase its use of fat during submaximal exercise of the same relative intensity in response to training remains to be elucidated.
This article has been cited by other articles:
![]() |
N. Turner, C. R. Bruce, S. M. Beale, K. L. Hoehn, T. So, M. S. Rolph, and G. J. Cooney Excess Lipid Availability Increases Mitochondrial Fatty Acid Oxidative Capacity in Muscle: Evidence Against a Role for Reduced Fatty Acid Oxidation in Lipid-Induced Insulin Resistance in Rodents Diabetes, August 1, 2007; 56(8): 2085 - 2092. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. B. Dokken and E. J. Henriksen Chronic selective glycogen synthase kinase-3 inhibition enhances glucose disposal and muscle insulin action in prediabetic obese Zucker rats Am J Physiol Endocrinol Metab, August 1, 2006; 291(2): E207 - E213. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Bach, D. Naon, S. Pich, F. X. Soriano, N. Vega, J. Rieusset, M. Laville, C. Guillet, Y. Boirie, H. Wallberg-Henriksson, et al. Expression of Mfn2, the Charcot-Marie-Tooth Neuropathy Type 2A Gene, in Human Skeletal Muscle: Effects of Type 2 Diabetes, Obesity, Weight Loss, and the Regulatory Role of Tumor Necrosis Factor {alpha} and Interleukin-6 Diabetes, September 1, 2005; 54(9): 2685 - 2693. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Saengsirisuwan, F. R. Perez, J. A. Sloniger, T. Maier, and E. J. Henriksen Interactions of exercise training and {alpha}-lipoic acid on insulin signaling in skeletal muscle of obese Zucker rats Am J Physiol Endocrinol Metab, September 1, 2004; 287(3): E529 - E536. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Bach, S. Pich, F. X. Soriano, N. Vega, B. Baumgartner, J. Oriola, J. R. Daugaard, J. Lloberas, M. Camps, J. R. Zierath, et al. Mitofusin-2 Determines Mitochondrial Network Architecture and Mitochondrial Metabolism. A NOVEL REGULATORY MECHANISM ALTERED IN OBESITY J. Biol. Chem., May 2, 2003; 278(19): 17190 - 17197. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. Wallis, C. M. Wheatley, S. Rattigan, E. J. Barrett, A. D.H. Clark, and M. G. Clark Insulin-Mediated Hemodynamic Changes Are Impaired in Muscle of Zucker Obese Rats Diabetes, December 1, 2002; 51(12): 3492 - 3498. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. J. Henriksen Exercise Effects of Muscle Insulin Signaling and Action: Invited Review: Effects of acute exercise and exercise training on insulin resistance J Appl Physiol, August 1, 2002; 93(2): 788 - 796. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. P. Turcotte, J. R. Swenberger, M. Zavitz Tucker, and A. J. Yee Increased Fatty Acid Uptake and Altered Fatty Acid Metabolism in Insulin-Resistant Muscle of Obese Zucker Rats Diabetes, June 1, 2001; 50(6): 1389 - 1396. [Abstract] [Full Text] |
||||
![]() |
A. A. Osman, J. Hancock, D. G. Hunt, J. L. Ivy, and L. J. Mandarino Exercise training increases ERK2 activity in skeletal muscle of obese Zucker rats J Appl Physiol, February 1, 2001; 90(2): 454 - 460. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. S. Buhl, N. Jessen, O. Schmitz, S. B. Pedersen, O. Pedersen, G. D. Holman, and S. Lund Chronic Treatment With 5-Aminoimidazole-4-Carboxamide-1-{beta}-D-Ribofuranoside Increases Insulin-Stimulated Glucose Uptake and GLUT4 Translocation in Rat Skeletal Muscles in a Fiber Type--Specific Manner Diabetes, January 1, 2001; 50(1): 12 - 17. [Abstract] [Full Text] |
||||
![]() |
M. S. Steen, K. R. Foianini, E. B. Youngblood, T. R. Kinnick, S. Jacob, and E. J. Henriksen Interactions of exercise training and ACE inhibition on insulin action in obese Zucker rats J Appl Physiol, June 1, 1999; 86(6): 2044 - 2051. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Cousin, S. Cinti, M. Morroni, S. Raimbault, D. Ricquier, L. Penicaud, and L. Casteilla Occurrence of brown adipocytes in rat white adipose tissue: molecular and morphological characterization J. Cell Sci., December 1, 1992; 103(4): 931 - 942. [Abstract] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |