TY - JOUR
T1 - Metabolic activity of brown, “beige,” and white adipose tissues in response to chronic adrenergic stimulation in male mice
AU - Labbé, Sébastien M.
AU - Caron, Alexandre
AU - Chechi, Kanta
AU - Laplante, Mathieu
AU - Lecomte, Roger
AU - Richard, Denis
N1 - Funding Information:
This work was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (2014-06721).
Publisher Copyright:
© 2016 the American Physiological Society.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Classical brown adipocytes such as those found in interscapular brown adipose tissue (iBAT) represent energy-burning cells, which have been postulated to play a pivotal role in energy metabolism. Brown adipocytes can also be found in white adipose tissue (WAT) depots [e.g., inguinal WAT (iWAT)] following adrenergic stimulation, and they have been referred to as “beige” adipocytes. Whether the presence of these adipocytes, which gives iWAT a beige appearance, can confer a white depot with some thermogenic activity remains to be seen. In consequence, we designed the present study to investigate the metabolic activity of iBAT, iWAT, and epididymal white depots in mice. Mice were either 1) kept at thermoneutrality (30°C), 2) kept at 30°C and treated daily for 14 days with an adrenergic agonist [CL-316,243 (CL)], or 3) housed at 10°C for 14 days. Metabolic activity was assessed using positron emission tomography imaging with fluoro- [ 18 F]deoxyglucose (glucose uptake), fluoro-[ 18 F]thiaheptadecanoic acid (fatty acid uptake), and [ 11 C]acetate (oxidative activity). In each group, substrate uptakes and oxidative activity were measured in anesthetized mice in response to acute CL. Our results revealed iBAT as a major site of metabolic activity, which exhibited enhanced glucose and nonesterified fatty acid uptakes and oxidative activity in response to chronic cold and CL. On the other hand, beige adipose tissue failed to exhibit appreciable increase in oxidative activity in response to chronic cold and CL. Altogether, our results suggest that the contribution of beige fat to acute-CL-induced metabolic activity is low compared with that of iBAT, even after sustained adrenergic stimulation.
AB - Classical brown adipocytes such as those found in interscapular brown adipose tissue (iBAT) represent energy-burning cells, which have been postulated to play a pivotal role in energy metabolism. Brown adipocytes can also be found in white adipose tissue (WAT) depots [e.g., inguinal WAT (iWAT)] following adrenergic stimulation, and they have been referred to as “beige” adipocytes. Whether the presence of these adipocytes, which gives iWAT a beige appearance, can confer a white depot with some thermogenic activity remains to be seen. In consequence, we designed the present study to investigate the metabolic activity of iBAT, iWAT, and epididymal white depots in mice. Mice were either 1) kept at thermoneutrality (30°C), 2) kept at 30°C and treated daily for 14 days with an adrenergic agonist [CL-316,243 (CL)], or 3) housed at 10°C for 14 days. Metabolic activity was assessed using positron emission tomography imaging with fluoro- [ 18 F]deoxyglucose (glucose uptake), fluoro-[ 18 F]thiaheptadecanoic acid (fatty acid uptake), and [ 11 C]acetate (oxidative activity). In each group, substrate uptakes and oxidative activity were measured in anesthetized mice in response to acute CL. Our results revealed iBAT as a major site of metabolic activity, which exhibited enhanced glucose and nonesterified fatty acid uptakes and oxidative activity in response to chronic cold and CL. On the other hand, beige adipose tissue failed to exhibit appreciable increase in oxidative activity in response to chronic cold and CL. Altogether, our results suggest that the contribution of beige fat to acute-CL-induced metabolic activity is low compared with that of iBAT, even after sustained adrenergic stimulation.
KW - Beige adipose tissue
KW - Brown adipose tissue
KW - Energy metabolism
KW - Oxidative metabolism
KW - Positron emission tomography
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U2 - 10.1152/ajpendo.00545.2015
DO - 10.1152/ajpendo.00545.2015
M3 - Article
C2 - 27143559
AN - SCOPUS:84983749205
SN - 0193-1849
VL - 311
SP - E260-E268
JO - American Journal of Physiology - Endocrinology and Metabolism
JF - American Journal of Physiology - Endocrinology and Metabolism
IS - 1
ER -