QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online January 17, 2007
Journal of Experimental Biology 210, 413-420 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.02660

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 Maillet, D. Articles by Weber, J.-M. Search for Related Content PubMed PubMed Citation Articles by Maillet, D. Articles by Weber, J.-M. Pubmed/NCBI databases Substance via MeSH Medline Plus Health Information Dietary Fats Social Bookmarking                         What's this?

Relationship between n-3 PUFA content and energy metabolism in the flight muscles of a migrating shorebird: evidence for natural doping

Dominique Maillet and Jean-Michel Weber^*

Biology Department, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada

^* Author for correspondence (e-mail: jmweber{at}uottawa.ca)

Accepted 21 November 2006

During their fall migration from the Arctic to South America, semipalmated sandpipers Calidris pusilla stop in the Bay of Fundy (east coast of Canada) before flying non-stop for 4500 km across the ocean. Refueling birds double their body mass by feeding on Corophium volutator, an amphipod containing high amounts of n-3 polyunsaturated fatty acids (n-3 PUFA), particularly eicosapentaenoic (20:5) and docosahexaenoic acid (22:6). In mammals, high dietary intake of n-3 PUFA is known to increase capacity for oxidative metabolism. Therefore, we hypothesized that tissue incorporation of n-3 PUFA would be associated with increases in the activity of key muscle enzymes to upregulate energy metabolism for prolonged exercise.

Birds were collected at various stages of fat loading to monitor changes in lipid composition and flight muscle enzymes simultaneously. Enzymes were measured to assess oxidative capacity [citrate synthase (CS)], ß-oxidation [carnitine palmitoyl transferase (CPT) and 3-hydroxyacyl dehydrogenase (HOAD)] and glycolytic capacity [lactate dehydrogenase (LDH)]. Changes in the fatty acid composition of muscle membranes (phospholipids) and fuel reserves (neutral lipids) were measured separately to distinguish between membrane-related and systemic effects of n-3 PUFA. Results show that muscle CS and HOAD are stimulated during refueling and that their activities are correlated with n-3 PUFA content in phospholipids (22:6 for CS, 20:5 for HOAD) and in neutral lipids (20:5 for CS). This suggests that 20:5 and 22:6 have different effects on energy metabolism and that they act via changes in membrane structure and systemic mechanisms. CPT and LDH did not change during refueling, but LDH activity was significantly related to the n-3 PUFA content of fuel reserves. This study shows that oxidative capacity increases rapidly during refueling and supports the idea that dietary n-3 PUFA are used as molecular signals to prime flight muscles of some long-distance migrants for extreme exercise.

Key words: dietary n-3 fatty acid, eicosapentaenoic acid, docosahexaenoic acid, long-distance migrant bird, semipalmated sandpiper, Calidris pusilla, muscle enzyme, endurance exercise

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				J. M. Klaiman, E. R. Price, and C. G. Guglielmo Fatty acid composition of pectoralis muscle membrane, intramuscular fat stores and adipose tissue of migrant and wintering white-throated sparrows (Zonotrichia albicollis) J. Exp. Biol., December 1, 2009; 212(23): 3865 - 3872. [Abstract] [Full Text] [PDF]

				E. R. Price and C. G. Guglielmo The effect of muscle phospholipid fatty acid composition on exercise performance: a direct test in the migratory white-throated sparrow (Zonotrichia albicollis) Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2009; 297(3): R775 - R782. [Abstract] [Full Text] [PDF]

				S. Nagahuedi, J. T. Popesku, V. L. Trudeau, and J.-M. Weber Mimicking the natural doping of migrant sandpipers in sedentary quails: effects of dietary n-3 fatty acids on muscle membranes and PPAR expression J. Exp. Biol., April 15, 2009; 212(8): 1106 - 1114. [Abstract] [Full Text] [PDF]

				J.-M. Weber The physiology of long-distance migration: extending the limits of endurance metabolism J. Exp. Biol., March 1, 2009; 212(5): 593 - 597. [Abstract] [Full Text] [PDF]

				A. R. Gerson, J. C. L. Brown, R. Thomas, M. A. Bernards, and J. F. Staples Effects of dietary polyunsaturated fatty acids on mitochondrial metabolism in mammalian hibernation J. Exp. Biol., August 15, 2008; 211(16): 2689 - 2699. [Abstract] [Full Text] [PDF]