Document Detail

Cold-acclimation in Peromyscus: temporal effects and individual variation in maximum metabolism and ventilatory traits.
MedLine Citation:
PMID:  14668313     Owner:  NLM     Status:  MEDLINE    
Thermal acclimation in small endotherms provides an excellent model for the study of physiological plasticity, as energy requirements can be easily manipulated and the results are relevant for natural conditions. Nevertheless, how physiology changes throughout acclimation, and how individuals vary in their response to acclimation, remain poorly understood. Here we describe a high temporal-resolution study of cold acclimation in the deer mouse Peromyscus maniculatus. The experimental design was based on repeated measures at short intervals throughout cold acclimation, with controls (maintained at constant temperature) for measurement artifacts. We monitored body mass, maximum metabolic rate in cold exposure and ventilatory traits (respiratory frequency, tidal and minute volume and oxygen extraction) for 3 weeks at 23 degrees C. Then, half of the individuals were held for 7 weeks at 5 degrees C. Body mass was differently affected by cold acclimation depending on sex. Maximal metabolism ((O(2)max)) increased significantly during the first week of cold acclimation, "overshot" after 5 weeks and dropped to a plateau about 34% above control values at week 7. Similarly, ventilatory traits increased during cold acclimation, though responses were different in their kinetics and magnitude. Body mass, maximum metabolism, and most ventilatory traits were repeatable after 7 weeks in control and cold-acclimated animals. However, repeatability tended to be lower in the cold-acclimated group, especially while animals were still acclimating. Our results show that acclimation effects may be under- and/or overestimated, depending on when trials are performed, and that different traits respond differently, and at different rates, to acclimation. Hence, future studies should be designed to ensure that animals have attained steady-state values in acclimation experiments.
Enrico L Rezende; Mark A Chappell; Kimberly A Hammond
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  The Journal of experimental biology     Volume:  207     ISSN:  0022-0949     ISO Abbreviation:  J. Exp. Biol.     Publication Date:  2004 Jan 
Date Detail:
Created Date:  2003-12-11     Completed Date:  2004-08-24     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0243705     Medline TA:  J Exp Biol     Country:  England    
Other Details:
Languages:  eng     Pagination:  295-305     Citation Subset:  IM    
Department of Biology, University of California-Riverside, Riverside, CA 92521, USA.
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MeSH Terms
Acclimatization / physiology*
Analysis of Variance
Body Constitution
Cold Temperature*
Energy Metabolism / physiology*
Peromyscus / physiology*
Pulmonary Ventilation / physiology*
Reproducibility of Results
Sex Factors
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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