TY - JOUR
T1 - Thermogenic changes with chronic cold exposure in the naked mole-rat (Heterocephalus glaber)
AU - Woodley, Ryan
AU - Buffenstein, Rochelle
N1 - Funding Information:
We thank the staff of the Central Animal Service of the University of the Witwatersrand, especially Mr Wilson Chai for his expert care of the animals. We also thank Shane Maloney, Duncan Mitchell and Craig Hartford for useful discussion during this study. This work was funded by an FRD grant to RB.
PY - 2002/11/1
Y1 - 2002/11/1
N2 - The naked mole-rat (Heterocephalus glaber) lives communally in a thermally buffered underground habitat. Here, it relies primarily on ectothermic (behavioral) mechanisms to maintain body temperature (Tb). Outside this milieu, it is unable to effectively regulate Tb and Tb tracks that of ambient temperature (Ta). Although naked mole-rats, in their natural habitat have little need for cold-tolerance, we questioned whether or not thermogenic capacity would change with prolonged (>1 year) exposure to cooler conditions. We hypothesized that these rodents would not conform to common mammalian patterns and that non-shivering thermogenic (NST) capacity would be unchanged with chronic cold exposure. The capacity for NST was assessed following noradrenaline administration (0.8 mg/kg, s.c.) to lightly anesthetized (pentobarbital 6% m/v 40 mg/kg) animals and monitoring the concomitant changes in oxygen consumption and Tb. Results concur with the null hypothesis in that prolonged cold exposure did not elicit any increase in NST capacity (1.52±0.17 ml O2/g/h, cold-acclimated; 1.73±0.31 ml O2/g/h, control; P>0.05). Rapid heat loss across their uninsulated integument may necessitate continuous maximal stimulation of brown adipose tissue (BAT), and as such, prevent any further increase in thermogenic capacity following cold exposure.
AB - The naked mole-rat (Heterocephalus glaber) lives communally in a thermally buffered underground habitat. Here, it relies primarily on ectothermic (behavioral) mechanisms to maintain body temperature (Tb). Outside this milieu, it is unable to effectively regulate Tb and Tb tracks that of ambient temperature (Ta). Although naked mole-rats, in their natural habitat have little need for cold-tolerance, we questioned whether or not thermogenic capacity would change with prolonged (>1 year) exposure to cooler conditions. We hypothesized that these rodents would not conform to common mammalian patterns and that non-shivering thermogenic (NST) capacity would be unchanged with chronic cold exposure. The capacity for NST was assessed following noradrenaline administration (0.8 mg/kg, s.c.) to lightly anesthetized (pentobarbital 6% m/v 40 mg/kg) animals and monitoring the concomitant changes in oxygen consumption and Tb. Results concur with the null hypothesis in that prolonged cold exposure did not elicit any increase in NST capacity (1.52±0.17 ml O2/g/h, cold-acclimated; 1.73±0.31 ml O2/g/h, control; P>0.05). Rapid heat loss across their uninsulated integument may necessitate continuous maximal stimulation of brown adipose tissue (BAT), and as such, prevent any further increase in thermogenic capacity following cold exposure.
KW - BAT
KW - Cold-acclimation
KW - Heterocephalus glaber
KW - Metabolism
KW - NST
KW - Naked mole-rat
KW - Non-shivering thermogenesis
KW - Thermogenic capacity
UR - http://www.scopus.com/inward/record.url?scp=0036849968&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036849968&partnerID=8YFLogxK
U2 - 10.1016/S1095-6433(02)00199-X
DO - 10.1016/S1095-6433(02)00199-X
M3 - Article
C2 - 12443938
AN - SCOPUS:0036849968
VL - 133
SP - 827
EP - 834
JO - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
JF - Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology
SN - 1095-6433
IS - 3
ER -