spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online October 19, 2007
Journal of Experimental Biology 210, 3749-3756 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.008763
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lurman, G. J.
Right arrow Articles by Pörtner, H.-O.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lurman, G. J.
Right arrow Articles by Pörtner, H.-O.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

An examination of the metabolic processes underpinning critical swimming in Atlantic cod (Gadus morhua L.) using in vivo 31P-NMR spectroscopy

Glenn J. Lurman*, Christian H. Bock and Hans-O. Pörtner

Alfred Wegener Institut fuer Polar und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany

* Author for correspondence (e-mail: Glenn.Lurman{at}awi.de)

Accepted 23 August 2007

Traditionally, critical swimming speed has been defined as the speed when a fish can no longer propel itself forward, and is exhausted. To gain a better understanding of the metabolic processes at work during a Ucrit swim test, and that lead to fatigue, we developed a method using in vivo 31P-NMR spectroscopy in combination with a Brett-type swim tunnel. Our data showed that a metabolic transition point is reached when the fish change from using steady state aerobic metabolism to non-steady state anaerobic metabolism, as indicated by a significant increase in inorganic phosphate levels from 0.3±0.3 to 9.5±3.4 mol g–1, and a drop in intracellular pH from 7.48±0.03 to 6.81±0.05 in muscle. This coincides with the point when the fish change gait from subcarangiform swimming to kick-and-glide bursts. As the number of kicks increased, so too did the Pi concentration, and the pHi dropped. Both changes were maximal at Ucrit. A significant drop in Gibbs free energy change of ATP hydrolysis from –55.6±1.4 to –49.8±0.7 kJ mol–1 is argued to have been involved in fatigue. This confirms earlier findings that the traditional definition of Ucrit, unlike other critical points that are typically marked by a transition from aerobic to anaerobic metabolism, is the point of complete exhaustion of both aerobic and anaerobic resources.

Key words: Atlantic cod, Gadus morhua, critical swimming speed, in vivo 31P-NMR spectroscopy, high-energy phosphates, Gibb's free energy, intracellular pH


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


This article has been cited by other articles:


Home page
 J. Exp. Biol.Home page
E. A. Jones, A. S. Jong, and D. J. Ellerby
The effects of acute temperature change on swimming performance in bluegill sunfish Lepomis macrochirus
J. Exp. Biol., May 1, 2008; 211(9): 1386 - 1393.
[Abstract] [Full Text] [PDF]


© The Company of Biologists Ltd 2007