Long photophase is not a sufficient stimulus to reduce thermogenic capacity in winter-acclimatized short-tailed field voles (Microtus agrestis) during long-term cold acclimation

R. M. McDevitt*, J. R. Speakman

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The thermogenic capacity of brown adipose tissue in winter- and summer-acclimatized short-tailed field voles (Microtus agrestis) was investigated by examining changes in mass of brown adipose tissue, the ratio of white adipose tissue to brown adipose tissue, the concentration of the uncoupling protein (thermogenin) in whole depots (μg) and in mitochondrial mass (μg·mg-1) and the activity of cytochrome c oxidase in the depots (mmol·min-1). The concentration of thermogenin in winter-acclimatized voles (n=8), per brown adipose tissue depot and per mitochondrial mass, was significantly higher than in summer-acclimatized voles (n=6). There was no significant difference in the level of cytochrome c oxidase activity between these two groups. Four groups of winter-acclimatized voles (n=6 in each group) were exposed to 5°C for 10, 20, 50 and 100 days in a 14L:10D photoperiod. Body mass, brown adipose tissue mass, white adipose tissue mass and basal metabolic rate were significantly positively related to the length of time cold exposed up to 100 days. There was a significant inverse relationship between the ratio of white to brown adipose tissue mass and the duration of cold exposure. There was no significant relationship between thermogenin concentration, either per depot or in mitochondrial mass of brown adipose tissue, with the length of time cold exposed. The level of cytochrome c oxidase activity increased significantly from control levels to a maximum after 10 days in the cold but decreased from 10 days onwards. In winter-acclimatized M. agrestis, a 14L:10D photoperiod is not a sufficient stimulus to reduce thermogenic capacity during cold acclimation. Indeed, some changes in the indirect parameters reflecting thermogenesis, notably the increase in basal metabolic rate and the decrease in the ratio of white to brown adipose tissue mass, indicated that despite the long photophase the thermogenic capacity was slightly further enhanced during the cold acclimation.

Original languageEnglish
Pages (from-to)159-164
Number of pages6
JournalJournal of Comparative Physiology B
Volume164
Issue number2
DOIs
Publication statusPublished - 30 Jun 1994

Fingerprint

Microtus agrestis
Arvicolinae
Brown Adipose Tissue
Acclimatization
brown adipose tissue
photophase
acclimation
Tissue
winter
Electron Transport Complex IV
Basal Metabolism
White Adipose Tissue
Photoperiod
cytochrome-c oxidase
white adipose tissue
cytochrome
basal metabolic rate
photoperiod
Thermogenesis
cold

Keywords

  • Brown adipose tissue
  • Cold acclimation
  • Field vole, Microtus agrestis
  • Long photophase
  • Thermogenic capacity

ASJC Scopus subject areas

  • Physiology
  • Ecology, Evolution, Behavior and Systematics
  • Biochemistry
  • Animal Science and Zoology
  • Endocrinology

Cite this

@article{e2c869f25a8e40cbb12e6075055f536b,
title = "Long photophase is not a sufficient stimulus to reduce thermogenic capacity in winter-acclimatized short-tailed field voles (Microtus agrestis) during long-term cold acclimation",
abstract = "The thermogenic capacity of brown adipose tissue in winter- and summer-acclimatized short-tailed field voles (Microtus agrestis) was investigated by examining changes in mass of brown adipose tissue, the ratio of white adipose tissue to brown adipose tissue, the concentration of the uncoupling protein (thermogenin) in whole depots (μg) and in mitochondrial mass (μg·mg-1) and the activity of cytochrome c oxidase in the depots (mmol·min-1). The concentration of thermogenin in winter-acclimatized voles (n=8), per brown adipose tissue depot and per mitochondrial mass, was significantly higher than in summer-acclimatized voles (n=6). There was no significant difference in the level of cytochrome c oxidase activity between these two groups. Four groups of winter-acclimatized voles (n=6 in each group) were exposed to 5°C for 10, 20, 50 and 100 days in a 14L:10D photoperiod. Body mass, brown adipose tissue mass, white adipose tissue mass and basal metabolic rate were significantly positively related to the length of time cold exposed up to 100 days. There was a significant inverse relationship between the ratio of white to brown adipose tissue mass and the duration of cold exposure. There was no significant relationship between thermogenin concentration, either per depot or in mitochondrial mass of brown adipose tissue, with the length of time cold exposed. The level of cytochrome c oxidase activity increased significantly from control levels to a maximum after 10 days in the cold but decreased from 10 days onwards. In winter-acclimatized M. agrestis, a 14L:10D photoperiod is not a sufficient stimulus to reduce thermogenic capacity during cold acclimation. Indeed, some changes in the indirect parameters reflecting thermogenesis, notably the increase in basal metabolic rate and the decrease in the ratio of white to brown adipose tissue mass, indicated that despite the long photophase the thermogenic capacity was slightly further enhanced during the cold acclimation.",
keywords = "Brown adipose tissue, Cold acclimation, Field vole, Microtus agrestis, Long photophase, Thermogenic capacity",
author = "McDevitt, {R. M.} and Speakman, {J. R.}",
year = "1994",
month = "6",
day = "30",
doi = "10.1007/BF00301659",
language = "English",
volume = "164",
pages = "159--164",
journal = "Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology",
issn = "0174-1578",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Long photophase is not a sufficient stimulus to reduce thermogenic capacity in winter-acclimatized short-tailed field voles (Microtus agrestis) during long-term cold acclimation

AU - McDevitt, R. M.

AU - Speakman, J. R.

PY - 1994/6/30

Y1 - 1994/6/30

N2 - The thermogenic capacity of brown adipose tissue in winter- and summer-acclimatized short-tailed field voles (Microtus agrestis) was investigated by examining changes in mass of brown adipose tissue, the ratio of white adipose tissue to brown adipose tissue, the concentration of the uncoupling protein (thermogenin) in whole depots (μg) and in mitochondrial mass (μg·mg-1) and the activity of cytochrome c oxidase in the depots (mmol·min-1). The concentration of thermogenin in winter-acclimatized voles (n=8), per brown adipose tissue depot and per mitochondrial mass, was significantly higher than in summer-acclimatized voles (n=6). There was no significant difference in the level of cytochrome c oxidase activity between these two groups. Four groups of winter-acclimatized voles (n=6 in each group) were exposed to 5°C for 10, 20, 50 and 100 days in a 14L:10D photoperiod. Body mass, brown adipose tissue mass, white adipose tissue mass and basal metabolic rate were significantly positively related to the length of time cold exposed up to 100 days. There was a significant inverse relationship between the ratio of white to brown adipose tissue mass and the duration of cold exposure. There was no significant relationship between thermogenin concentration, either per depot or in mitochondrial mass of brown adipose tissue, with the length of time cold exposed. The level of cytochrome c oxidase activity increased significantly from control levels to a maximum after 10 days in the cold but decreased from 10 days onwards. In winter-acclimatized M. agrestis, a 14L:10D photoperiod is not a sufficient stimulus to reduce thermogenic capacity during cold acclimation. Indeed, some changes in the indirect parameters reflecting thermogenesis, notably the increase in basal metabolic rate and the decrease in the ratio of white to brown adipose tissue mass, indicated that despite the long photophase the thermogenic capacity was slightly further enhanced during the cold acclimation.

AB - The thermogenic capacity of brown adipose tissue in winter- and summer-acclimatized short-tailed field voles (Microtus agrestis) was investigated by examining changes in mass of brown adipose tissue, the ratio of white adipose tissue to brown adipose tissue, the concentration of the uncoupling protein (thermogenin) in whole depots (μg) and in mitochondrial mass (μg·mg-1) and the activity of cytochrome c oxidase in the depots (mmol·min-1). The concentration of thermogenin in winter-acclimatized voles (n=8), per brown adipose tissue depot and per mitochondrial mass, was significantly higher than in summer-acclimatized voles (n=6). There was no significant difference in the level of cytochrome c oxidase activity between these two groups. Four groups of winter-acclimatized voles (n=6 in each group) were exposed to 5°C for 10, 20, 50 and 100 days in a 14L:10D photoperiod. Body mass, brown adipose tissue mass, white adipose tissue mass and basal metabolic rate were significantly positively related to the length of time cold exposed up to 100 days. There was a significant inverse relationship between the ratio of white to brown adipose tissue mass and the duration of cold exposure. There was no significant relationship between thermogenin concentration, either per depot or in mitochondrial mass of brown adipose tissue, with the length of time cold exposed. The level of cytochrome c oxidase activity increased significantly from control levels to a maximum after 10 days in the cold but decreased from 10 days onwards. In winter-acclimatized M. agrestis, a 14L:10D photoperiod is not a sufficient stimulus to reduce thermogenic capacity during cold acclimation. Indeed, some changes in the indirect parameters reflecting thermogenesis, notably the increase in basal metabolic rate and the decrease in the ratio of white to brown adipose tissue mass, indicated that despite the long photophase the thermogenic capacity was slightly further enhanced during the cold acclimation.

KW - Brown adipose tissue

KW - Cold acclimation

KW - Field vole, Microtus agrestis

KW - Long photophase

KW - Thermogenic capacity

UR - http://www.scopus.com/inward/record.url?scp=0028010672&partnerID=8YFLogxK

U2 - 10.1007/BF00301659

DO - 10.1007/BF00301659

M3 - Article

VL - 164

SP - 159

EP - 164

JO - Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology

JF - Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology

SN - 0174-1578

IS - 2

ER -