HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 285/5/R1165    most recent 00238.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science 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 ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Buchanan, J. B. Articles by Satinoff, E. Search for Related Content PubMed PubMed Citation Articles by Buchanan, J. B. Articles by Satinoff, E.

INFLAMMATION, CYTOKINES, AND TEMPERATURE REGULATION

Thermoregulatory and metabolic changes during fever in young and old rats

Department of Psychology and Program in Neuroscience, University of Delaware, Newark, Delaware 19716-2590

Submitted 1 May 2003 ; accepted in final form 25 July 2003

We injected old and young rats with lipopolysaccharide (LPS; 50 µg/kg ip) at two ambient temperatures (T_a; 21 and 31°C). Young rats mounted equivalent fevers at both T_as [peak body temperatures (T_b) of 38.3 and 38.7°C, respectively]. The T_b of old rats was not different from baseline (37.3°C) after LPS at T_a 21°C, whereas, at 31°C, their T_b rose to a mean peak of 38.4°C. We also measured the associated thermoregulatory responses by use of calorimetry. At 21°C, young rats developed a fever by increasing both O₂ consumption and heat conservation. Old rats did not become febrile, and O₂ consumption fell by 15%. Heat loss was the same in old and young rats. At 31°C, young and old rats developed similar fevers with similar increases in heat production and conservation. Our results suggest that the lack of LPS fever in old rats at 21°C is due mainly to the lowered metabolic rate.

aging; heat production; heat loss; ambient temperature; lipopolysaccharide

This article has been cited by other articles:

				J. B. Buchanan, E. Peloso, and E. Satinoff A warmer ambient temperature increases the passage of interleukin-1{beta} into the brains of old rats Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2008; 295(1): R361 - R368. [Abstract] [Full Text] [PDF]

				A. A. Romanovsky Anorexia: the toll for lipopolysaccharide recognition Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2004; 287(2): R274 - R275. [Full Text] [PDF]