Alterations in endogenous circadian rhythm of core temperature in senescent Fischer 344 rats

Roger B. Mcdonald, Tana M. Hoban-Higgins, Rodney C. Ruhe, Charles A. Fuller, Barbara A Horwitz

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

We assessed whether alterations in endogenous circadian rhythm of core temperature (CRT) in aging rats are associated with chronological time or with a biological marker of senescence, i.e., spontaneous rapid body weight loss. CRT was measured in male Fischer 344 (F344) rats beginning at age 689 days and then continuously until death. Young rats were also monitored. The rats were housed under constant dim red light at 24-26°C, and core temperature was recorded every 10 min via biotelemetry. The CRT amplitude of the body weight-stable (presenescent) old rats was significantly less than that of young rats at all analysis periods. At the onset of spontaneous rapid weight loss (senescence), all measures of endogenous CRT differed significantly from those in the presenescent period. The suprachiasmatic nucleus (a circadian pacemaker) of the senescent rats maintained its light responsiveness as determined by an increase in c-fos expression after a brief light exposure. These data demonstrate that some characteristics of the CRT are altered slowly with chronological aging, whereas others occur rapidly with the onset of senescence.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume276
Issue number3 45-3
StatePublished - Mar 1999

Fingerprint

Inbred F344 Rats
Circadian Rhythm
Temperature
Light
Weight Loss
Body Weight
Suprachiasmatic Nucleus
Biomarkers
Demography

Keywords

  • Age-related anorexia
  • Aging
  • Biological age
  • Hypothalamus
  • Suprachiasmatic nucleus

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

Alterations in endogenous circadian rhythm of core temperature in senescent Fischer 344 rats. / Mcdonald, Roger B.; Hoban-Higgins, Tana M.; Ruhe, Rodney C.; Fuller, Charles A.; Horwitz, Barbara A.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 276, No. 3 45-3, 03.1999.

Research output: Contribution to journalArticle

Mcdonald, Roger B. ; Hoban-Higgins, Tana M. ; Ruhe, Rodney C. ; Fuller, Charles A. ; Horwitz, Barbara A. / Alterations in endogenous circadian rhythm of core temperature in senescent Fischer 344 rats. In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology. 1999 ; Vol. 276, No. 3 45-3.
@article{8dc0ec46259d4352ad3c52f0d41fa0c5,
title = "Alterations in endogenous circadian rhythm of core temperature in senescent Fischer 344 rats",
abstract = "We assessed whether alterations in endogenous circadian rhythm of core temperature (CRT) in aging rats are associated with chronological time or with a biological marker of senescence, i.e., spontaneous rapid body weight loss. CRT was measured in male Fischer 344 (F344) rats beginning at age 689 days and then continuously until death. Young rats were also monitored. The rats were housed under constant dim red light at 24-26°C, and core temperature was recorded every 10 min via biotelemetry. The CRT amplitude of the body weight-stable (presenescent) old rats was significantly less than that of young rats at all analysis periods. At the onset of spontaneous rapid weight loss (senescence), all measures of endogenous CRT differed significantly from those in the presenescent period. The suprachiasmatic nucleus (a circadian pacemaker) of the senescent rats maintained its light responsiveness as determined by an increase in c-fos expression after a brief light exposure. These data demonstrate that some characteristics of the CRT are altered slowly with chronological aging, whereas others occur rapidly with the onset of senescence.",
keywords = "Age-related anorexia, Aging, Biological age, Hypothalamus, Suprachiasmatic nucleus",
author = "Mcdonald, {Roger B.} and Hoban-Higgins, {Tana M.} and Ruhe, {Rodney C.} and Fuller, {Charles A.} and Horwitz, {Barbara A}",
year = "1999",
month = "3",
language = "English (US)",
volume = "276",
journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
issn = "1931-857X",
publisher = "American Physiological Society",
number = "3 45-3",

}

TY - JOUR

T1 - Alterations in endogenous circadian rhythm of core temperature in senescent Fischer 344 rats

AU - Mcdonald, Roger B.

AU - Hoban-Higgins, Tana M.

AU - Ruhe, Rodney C.

AU - Fuller, Charles A.

AU - Horwitz, Barbara A

PY - 1999/3

Y1 - 1999/3

N2 - We assessed whether alterations in endogenous circadian rhythm of core temperature (CRT) in aging rats are associated with chronological time or with a biological marker of senescence, i.e., spontaneous rapid body weight loss. CRT was measured in male Fischer 344 (F344) rats beginning at age 689 days and then continuously until death. Young rats were also monitored. The rats were housed under constant dim red light at 24-26°C, and core temperature was recorded every 10 min via biotelemetry. The CRT amplitude of the body weight-stable (presenescent) old rats was significantly less than that of young rats at all analysis periods. At the onset of spontaneous rapid weight loss (senescence), all measures of endogenous CRT differed significantly from those in the presenescent period. The suprachiasmatic nucleus (a circadian pacemaker) of the senescent rats maintained its light responsiveness as determined by an increase in c-fos expression after a brief light exposure. These data demonstrate that some characteristics of the CRT are altered slowly with chronological aging, whereas others occur rapidly with the onset of senescence.

AB - We assessed whether alterations in endogenous circadian rhythm of core temperature (CRT) in aging rats are associated with chronological time or with a biological marker of senescence, i.e., spontaneous rapid body weight loss. CRT was measured in male Fischer 344 (F344) rats beginning at age 689 days and then continuously until death. Young rats were also monitored. The rats were housed under constant dim red light at 24-26°C, and core temperature was recorded every 10 min via biotelemetry. The CRT amplitude of the body weight-stable (presenescent) old rats was significantly less than that of young rats at all analysis periods. At the onset of spontaneous rapid weight loss (senescence), all measures of endogenous CRT differed significantly from those in the presenescent period. The suprachiasmatic nucleus (a circadian pacemaker) of the senescent rats maintained its light responsiveness as determined by an increase in c-fos expression after a brief light exposure. These data demonstrate that some characteristics of the CRT are altered slowly with chronological aging, whereas others occur rapidly with the onset of senescence.

KW - Age-related anorexia

KW - Aging

KW - Biological age

KW - Hypothalamus

KW - Suprachiasmatic nucleus

UR - http://www.scopus.com/inward/record.url?scp=0032920073&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032920073&partnerID=8YFLogxK

M3 - Article

C2 - 10070144

AN - SCOPUS:0032920073

VL - 276

JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

SN - 1931-857X

IS - 3 45-3

ER -