|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 199, Issue 8 1689-1697, Copyright © 1996 by Company of Biologists
JOURNAL ARTICLES |
R Vock, H Hoppeler, H Claassen, DX Wu, R Billeter, JM Weber, CR Taylor and ER Weibel
Department of Anatomy, University of Berne, Switzerland.
This paper quantifies the structures involved in the transport and oxidation of carbohydrates and fatty acids within the muscle cell. The structural capacity is measured on whole-body random samples of the musculature of dogs and pygmy goats and compared with maximal rates of oxygen consumption and substrate oxidation. Comparing dogs and goats of the same body size provided a 1.55-fold difference in the maximal rate of oxidation when related to muscle mass. As in previous studies, we found that the volume of mitochondria was approximately proportional to aerobic capacity. The maximal glucose flux from intracellular stores to mitochondria is 1.6 times greater in the dog than in the goat; we find that the amount of glycogen stored in the muscle cells is 4.2 times as great in the dog, but part of the intracellular glycogen pool is used for anaerobic rather than for oxidative metabolism. The maximal fatty acid flux from intracellular stores to mitochondria is 1.5 times larger in the dog, and the amount of lipid stored is 2.3 times as great in the dog. Every lipid droplet is in direct contact with the outer membrane of a mitochondrion and the contact surface area is 3.6 times greater in the dog than in the goat. Additional measurements are needed to investigate the role of structural limitation at this step. The amount of substrates stored intracellularly in the muscle cells of the dog is about twice as much as would match the differences in the maximal rates of utilization. This allows the endurance-specialized dogs to run for longer periods at higher rates of oxidation.
This article has been cited by other articles:
|
|
 |
|
  S. Martin, K. Driessen, S. J. Nixon, M. Zerial, and R. G. Parton Regulated Localization of Rab18 to Lipid Droplets: EFFECTS OF LIPOLYTIC STIMULATION AND INHIBITION OF LIPID DROPLET CATABOLISM J. Biol. Chem., December 23, 2005; 280(51): 42325 - 42335. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Zhou, J. E. Salem, G. M. Saidel, W. C. Stanley, and M. E. Cabrera Mechanistic model of cardiac energy metabolism predicts localization of glycolysis to cytosolic subdomain during ischemia Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2400 - H2411. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. R. Kashyap, R. Belfort, R. Berria, S. Suraamornkul, T. Pratipranawatr, J. Finlayson, A. Barrentine, M. Bajaj, L. Mandarino, R. DeFronzo, et al. Discordant effects of a chronic physiological increase in plasma FFA on insulin signaling in healthy subjects with or without a family history of type 2 diabetes Am J Physiol Endocrinol Metab, September 1, 2004; 287(3): E537 - E546. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. W. Helge and F. Dela Effect of Training on Muscle Triacylglycerol and Structural Lipids: A Relation to Insulin Sensitivity? Diabetes, August 1, 2003; 52(8): 1881 - 1887. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. W. Helge, C. Lundby, D. L. Christensen, J. Langfort, L. Messonnier, M. Zacho, J. L. Andersen, and B. Saltin Skiing across the Greenland icecap: divergent effects on limb muscle adaptations and substrate oxidation J. Exp. Biol., March 15, 2003; 206(6): 1075 - 1083. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Hoppeler and M. Fluck Normal mammalian skeletal muscle and its phenotypic plasticity J. Exp. Biol., August 1, 2002; 205(15): 2143 - 2152. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Howald, C. Boesch, R. Kreis, S. Matter, R. Billeter, B. Essen-Gustavsson, and H. Hoppeler Content of intramyocellular lipids derived by electron microscopy, biochemical assays, and 1H-MR spectroscopy J Appl Physiol, June 1, 2002; 92(6): 2264 - 2272. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Larson-Meyer, B. R. Newcomer, and G. R. Hunter Influence of endurance running and recovery diet on intramyocellular lipid content in women: a 1H NMR study Am J Physiol Endocrinol Metab, January 1, 2002; 282(1): E95 - E106. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Boden, B. Lebed, M. Schatz, C. Homko, and S. Lemieux Effects of Acute Changes of Plasma Free Fatty Acids on Intramyocellular Fat Content and Insulin Resistance in Healthy Subjects Diabetes, July 1, 2001; 50(7): 1612 - 1617. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. W. Helge, B. J. Wu, M. Willer, J. R. Daugaard, L. H. Storlien, and B. Kiens Training affects muscle phospholipid fatty acid composition in humans J Appl Physiol, February 1, 2001; 90(2): 670 - 677. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. F Coyle Physical activity as a metabolic stressor Am. J. Clinical Nutrition, August 1, 2000; 72(2): 512S - 520. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. R. Pendergast, J. J. Leddy, and J. T. Venkatraman A Perspective on Fat Intake in Athletes J. Am. Coll. Nutr., June 1, 2000; 19(3): 345 - 350. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. S. Szczepaniak, E. E. Babcock, F. Schick, R. L. Dobbins, A. Garg, D. K. Burns, J. D. McGarry, and D. T. Stein Measurement of intracellular triglyceride stores by H spectroscopy: validation in vivo Am J Physiol Endocrinol Metab, May 1, 1999; 276(5): E977 - E989. [Abstract] [Full Text] [PDF]
|
|
