AJP - Regulatory, Integrative and Comparative Physiology, Vol 248, Issue 2 231-R235, Copyright © 1985 by American Physiological Society
Brown adipose tissue lipectomy leads to increased fat deposition in Osborne-Mendel rats
B. J. Moore, T. Inokuchi, J. S. Stern and B. A. Horwitz
Inter- and subscapular brown adipose tissue depots were removed from nine
female Osborne-Mendel rats. These lipectomized animals and nine
sham-operated controls recovered from surgery for 7 days at 25 degrees C
and were then placed on a highly palatable liquid diet. All animals were
maintained for a 2nd wk at 25 degrees C before being switched to 8 degrees
C. After 9 wk in the cold, animals were killed, and the brown adipose
tissue was dissected from scapular, cervical, thoracic, perirenal, and
axillary regions. Total brown fat pad mass, protein content, brown
adipocyte number, citrate synthase activity, and beta-hydroxyacyl CoA
dehydrogenase activity in each of the dissected brown fat depots were
significantly less than those of the sham-operated controls. Thus there was
incomplete metabolic compensation in the remaining brown fat depots after
the removal of the scapular brown fat in the lipectomized rats. The mass
and lipid content of the retroperitoneal white adipose depot were
significantly increased in the lipectomized rats as was their carcass fat
content (up 14%). Food intake of the lipectomized rats was slightly but
significantly decreased. These data indicate that a reduction in the amount
of functional brown fat is accompanied by increased body fat accretion and
are thus consistent with the hypothesis that decreased brown adipose
thermogenesis can lead to altered energy balance and increased white fat
deposition.
