HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Duchamp, C Articles by Barré, H Search for Related Content PubMed PubMed Citation Articles by Duchamp, C Articles by Barré, H

Laboratoire de Thermorégulation et Energétique de l'Exercise, URA 1341 CNRS, Lyon, France.

1. The histochemical characteristics of gastrocnemius muscle were investigated in 6-week-old cold-acclimated (5 weeks, 4 degrees C) and glucagon-treated (5 weeks, 25 degrees C, 103 nmol/kg I.P. twice daily) muscovy ducklings, two groups able to develop non-shivering thermogenesis in vivo. A comparison was made with thermoneutral controls (25 degrees C) of the same age. All animals were fed ad libitum. Fibre type, fibre area and capillary supply have been studied. Further, a quantitative histochemical method for mitochondrial Mg(2+)-ATPase activity was developed to characterize the mitochondrial coupling state in situ. 2. White gastrocnemius was composed of fast glycolytic (FG) and fast oxidative glycolytic (FOG) fibres, while red gastrocnemius contained FOG and slow oxidative (SO) fibres. In white gastrocnemius, the proportion of FG fibres was higher in glucagon-treated than in control or cold-acclimated ducklings. In red gastrocnemius, the proportion of SO fibres was higher in both cold-acclimated and glucagon-treated ducklings than in controls. The area of all fibres was generally lower in glucagon-treated than in other ducklings. 3. The capillary density was higher in both red and white components of the gastrocnemius muscle in cold-acclimated and glucagon-treated than in control ducklings, as a result of an increased number of capillaries around each fibre. 4. In all fibres, except the FG type in cold-acclimated ducklings, the staining intensity of the Mg(2+)-ATPase reaction was higher in cold-acclimated and glucagon-treated than in control ducklings whereas the staining intensity with maximal decoupling of oxidative phosphorylation by dinitrophenol was unchanged. This indicated a more loose-coupled state of mitochondria in situ in all fibres of cold-acclimated ducklings, and in FOG fibres of white gastrocnemius and SO fibres of red gastrocnemius in glucagon-treated ducklings. 5. These results indicated a higher oxidative metabolism of skeletal muscle in both cold-acclimated and glucagon-treated than in control ducklings, and for most of the parameters studied, a similarity between cold acclimation and glucagon treatment. Because of the higher loose-coupled state of muscle mitochondria in cold-acclimated and glucagon-treated than in control ducklings, the higher oxidative capacity of skeletal muscle in these ducklings could be used for heat production rather than ATP synthesis and account for muscular non-shivering thermogenesis.

This article has been cited by other articles:

				B. Rey, L. G. Halsey, V. Dolmazon, J.-L. Rouanet, D. Roussel, Y. Handrich, P. J. Butler, and C. Duchamp Long-term fasting decreases mitochondrial avian UCP-mediated oxygen consumption in hypometabolic king penguins Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2008; 295(1): R92 - R100. [Abstract] [Full Text] [PDF]

				D. R. Jensen, L. A. Knaub, J. P. Konhilas, L. A. Leinwand, P. S. MacLean, and R. H. Eckel Increased thermoregulation in cold-exposed transgenic mice overexpressing lipoprotein lipase in skeletal muscle: an avian phenotype? J. Lipid Res., April 1, 2008; 49(4): 870 - 879. [Abstract] [Full Text] [PDF]

				P. J. Schaeffer, J. J. Villarin, D. J. Pierotti, D. P. Kelly, and S. L. Lindstedt Cost of transport is increased after cold exposure in Monodelphis domestica: training for inefficiency J. Exp. Biol., August 15, 2005; 208(16): 3159 - 3167. [Abstract] [Full Text] [PDF]

				M. Hirabayashi, D. Ijiri, Y. Kamei, A. Tajima, and Y. Kanai Transformation of Skeletal Muscle from Fast- to Slow-Twitch during Acquisition of Cold Tolerance in the Chick Endocrinology, January 1, 2005; 146(1): 399 - 405. [Abstract] [Full Text] [PDF]

				C. Benistant, C. Duchamp, F. Cohen-Adad, J.-L. Rouanet, and H. Barre Increased in vitro fatty acid supply and cellular transport capacities in cold-acclimated ducklings (Cairina moschata) Am J Physiol Regulatory Integrative Comp Physiol, September 1, 1998; 275(3): R683 - R690. [Abstract] [Full Text] [PDF]

				F. Marmonier, C. Duchamp, F. Cohen-Adad, T. P. D. Eldershaw, and H. Barre Hormonal control of thermogenesis in perfused muscle of Muscovy ducklings Am J Physiol Regulatory Integrative Comp Physiol, November 1, 1997; 273(5): R1638 - R1648. [Abstract] [Full Text] [PDF]