Journal of Stress Physiology &
Biochemistry, Vol.
8 No. 4
2012, pp. 226-235 ISSN 1997-0838
Original Text Copyright (cc) 2012 by Zhang, Gao, Jiang, Wang
ORIGINAL
ARTICLE
Data source : Google Scholar
QueryDate : 2016-12-24
Cites : 1
The relationship among
metabolic rate of tree shrews (Tupaia
belangeri) under cold acclimation
1School
of life Sciences, Yunnan Normal University, Kunming 650500, Yunnan
Province, People’s Republic of China
2Institutes of Hydrobiology, the Chinese Academy of Sciences,
Wuhan 430072, Hubei Province, People’s Republic of China
§Lin Zhang and Wenrong Gao contributed equally to this work
Many small mammals inhabiting cold
environments display enhanced capacity for seasonal changes in
nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic
rate (MMR). However, it is not known how this plasticity remains in a
mammal that rarely experiences extreme cold fluctuations. In order to
answer this question, we determined body mass ( Mb), basal metabolic
rate (BMR), NST, and MMR on a tree shrews (Tupaia belangeri),
acclimated to cold (5 ēC) conditions. NST was measured as the maximum
response of metabolic rate (NSTmax) after injection of norepinephrine
(NE) in thermoneutrality minus BMR. Maximum metabolic rate was assessed
in animals exposed to enhanced heat-loss atmosphere (He-O2)
connected with an open-flow respirometer. Body mass and metabolic
variables increased significantly after cold acclimation with respect
to control group but to a high extent (BMR, 87.97%; NST, 69.77%; and
MMR, 32.35%). However, aerobic scope (MMR/BMR), and calculated
shivering thermogenesis (ST) did not significantly change with control
group. Our data suggest: 1). The body mass and the capacity of heat
production in the cold acclimated group were higher; 2). The increase
of BMR and MMR during cold acclimation was the main pattern of heat
production in the tree shrews.
Key
words: Cold acclimation; metabolic rate; Tupaia belangeri;
thermogenesis plasticity
