|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 202, Issue 20 2839-2849, Copyright © 1999 by Company of Biologists
JOURNAL ARTICLES |
E Krol and JR Speakman
Aberdeen Centre for Energy Regulation and Obesity, Department of Zoology, University of Aberdeen, Aberdeen AB24 2TZ, UK. J.Speakman@abdn.ac.uk
The isotope dilution technique for measuring total body water (TBW), and the doubly labelled water (DLW) method for measuring energy expenditure, are both sensitive to small variations in the ratio of the hydrogen to oxygen-18 dilution space. Since the dilution space ratio varies between individuals, there has been much recent debate over what causes this variability (i.e. physiological differences between individuals or analytical error in the isotope determinations), and thus which values (individual or a population mean dilution space ratio) should be employed for TBW and DLW calculations. To distinguish between physiological and analytical variability, we injected 15 non-reproductive and 12 lactating mice (Mus musculus, outbred MF1) simultaneously with deuterium, tritium and oxygen-18. The two hydrogen labels were administered and analysed independently, therefore we expected a strong correlation between dilution space ratios based on deuterium and tritium if most of the variation in dilution spaces was physiological, but only a weak correlation if most of the variation was analytical. Dilution spaces were significantly influenced by reproductive status. Dilution spaces expressed as a percentage of body mass averaged 15.7 % greater in lactating mice than in non-reproductive mice. In addition, the hydrogen tracer employed had a significant effect (deuterium spaces were 2.0 % larger than tritium spaces). Deuterium and tritium dilution spaces, expressed as a percentage of body mass, were highly correlated. Dilution space ratios ranged from 0.952 to 1. 146 when using deuterium, and from 0.930 to 1.103 when using tritium. Dilution space ratios based on deuterium and tritium were also highly correlated. Comparison of standard deviations of the dilution space ratio based on deuterium in vivo and in vitro indicated that only 4.5 % of the variation in the dilution space ratios observed in the mice could be accounted for by analytical variation in the deuterium and oxygen-18 analyses. Although our results include data which were outside the limits previously regarded as biologically possible, the correlations that we detected strongly suggest that variation in the observed dilution space ratio was mostly physiological rather than analytical.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  S.-H. Wu, L.-N. Zhang, J. R. Speakman, and D.-H. Wang Limits to sustained energy intake. XI. A test of the heat dissipation limitation hypothesis in lactating Brandt's voles (Lasiopodomys brandtii) J. Exp. Biol., November 1, 2009; 212(21): 3455 - 3465. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. T. Jones, M. D. Hastings, B. L. Bostrom, R. D. Andrews, and D. R. Jones Validation of the use of doubly labeled water for estimating metabolic rate in the green turtle (Chelonia mydas L.): a word of caution J. Exp. Biol., August 15, 2009; 212(16): 2635 - 2644. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Zub, P.A. Szafranska, M. Konarzewski, P. Redman, and J.R. Speakman Trade-offs between activity and thermoregulation in a small carnivore, the least weasel Mustela nivalis Proc R Soc B, May 22, 2009; 276(1663): 1921 - 1927. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. D. Williams, F. Vezina, and J. R. Speakman Individually variable energy management during egg production is repeatable across breeding attempts J. Exp. Biol., April 15, 2009; 212(8): 1101 - 1105. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Schubert, L. M. Vaanholt, F. Stavasius, G. E. Demas, S. Daan, and G. H. Visser Female mice respond differently to costly foraging versus food restriction J. Exp. Biol., July 15, 2008; 211(14): 2214 - 2223. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Krol, M. Murphy, and J. R. Speakman Limits to sustained energy intake. X. Effects of fur removal on reproductive performance in laboratory mice J. Exp. Biol., December 1, 2007; 210(23): 4233 - 4243. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M Scantlebury, J.M Waterman, M Hillegass, J.R Speakman, and N.C Bennett Energetic costs of parasitism in the Cape ground squirrel Xerus inauris Proc R Soc B, September 7, 2007; 274(1622): 2169 - 2177. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Bennett, J. R. Speakman, S. E. W. Moss, P. Pomeroy, and M. A. Fedak Effects of mass and body composition on fasting fuel utilisation in grey seal pups (Halichoerus grypus Fabricius): an experimental study using supplementary feeding J. Exp. Biol., September 1, 2007; 210(17): 3043 - 3053. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Ward, U. Moller, J. M. V. Rayner, D. M. Jackson, W. Nachtigall, and J. R. Speakman Metabolic power of European starlings Sturnus vulgaris during flight in a wind tunnel, estimated from heat transfer modelling, doubly labelled water and mask respirometry J. Exp. Biol., November 15, 2004; 207(24): 4291 - 4298. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Krol and J. R. Speakman Limits to sustained energy intake VII. Milk energy output in laboratory mice at thermoneutrality J. Exp. Biol., December 1, 2003; 206(23): 4267 - 4281. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Krol, M. S. Johnson, and J. R. Speakman Limits to sustained energy intake VIII. Resting metabolic rate and organ morphology of laboratory mice lactating at thermoneutrality J. Exp. Biol., December 1, 2003; 206(23): 4283 - 4291. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Speakman, T. Ergon, R. Cavanagh, K. Reid, D. M. Scantlebury, and X. Lambin Resting and daily energy expenditures of free-living field voles are positively correlated but reflect extrinsic rather than intrinsic effects PNAS, November 25, 2003; 100(24): 14057 - 14062. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Brommage Validation and calibration of DEXA body composition in mice Am J Physiol Endocrinol Metab, September 1, 2003; 285(3): E454 - E459. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C Selman, S Lumsden, L Bunger, W. Hill, and J. Speakman Resting metabolic rate and morphology in mice (Mus musculus) selected for high and low food intake J. Exp. Biol., January 2, 2001; 204(4): 777 - 784. [Abstract] [PDF]
|
|
