Document Detail


Nocturnal shifts in thermal and metabolic responses of the immature rat.
MedLine Citation:
PMID:  3391910     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Immature rats were tested at 2, 7, 11, and 15 days of age to determine steady-state thermoregulatory responses during light (L) and dark (D) phases of the daily cycle. Pups were housed with dams in a vivarium illuminated from 0700 to 1900 h. During each phase tests began approximately 1 h after the change in the light conditions of the vivarium. Duration of each test was approximately 7 h. Rats were tested individually in temperature-controlled cylinders at ambient temperatures (Ta) = 25.0, 30.0, 32.5, and 35.0 degrees C. Both colonic (Tco) and tail skin temperatures of each animal were measured continuously. O2 content of effluent air from each cylinder was determined to provide an estimate of metabolic rate (M). Immature rats, at 2 to 11 days of age, exhibited significant L:D differences in M and Tco. However, no significant L:D differences in these responses were noted at 15 days of age. In every case, nocturnal increases in Tco were associated with a rise in M. L:D differences in Tco response were not attributed to a significant change in total thermal conductance. These data support the conclusion that the immature rat exhibits daily variation in metabolic rate, which is the primary contributor to L:D shifts in Tco.
Authors:
D E Spiers
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  64     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1988 May 
Date Detail:
Created Date:  1988-08-17     Completed Date:  1988-08-17     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2119-24     Citation Subset:  IM    
Affiliation:
John B. Pierce Foundation Laboratory, Yale University School of Medicine, New Haven, Connecticut 06519.
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MeSH Terms
Descriptor/Qualifier:
Animals
Animals, Newborn / metabolism,  physiology*
Body Temperature Regulation*
Circadian Rhythm*
Darkness
Light
Rats
Rats, Inbred Strains
Grant Support
ID/Acronym/Agency:
HD-18002/HD/NICHD NIH HHS

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


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