Regional differences in adipose tissue lipolysis from lean and
obese women: existence of post-receptor alterations.
Mauri[grave]ege, P., D. Prud'homme, S. Lemieux, A. Tremblay, and J. P.
Despr[acute]es.
Physical Activity Sciences Laboratory, Laval University, Lipid
Research Center, CHUL Medical Research Center, Ste-Foy,
Qu[acute]ebec, Canada
APStracts 2:0058E, 1995.
Lipolysis studies were performed on isolated adipose cells obtained
from two subcutaneous regions (abdominal and femoral) in 26
premenopausal women (16 obese and 10 lean subjects). As obese
adipocytes from both sites were significantly larger than lean fat
cells, glycerol release measured by an ultrasensitive bioluminescent
method was corrected for variation in cell surface area. Epinephrine
induced antilipolysis at low concentrations, and a net lipolytic
response at higher doses, irrespective of both the subjects' fatness
and the anatomic location of fat. However, the catecholamine and the
selective [alpha]2-adrenergic agonist, UK 14304, promoted a greater
maximal antilipolytic response in both femoral and subcutaneous
abdominal adipose cells from obese than in those from lean
individuals. Epinephrine- and UK 14304-induced maximal antilipolyses
of femoral adipocytes were also positively associated with indicators
of total adiposity. On the other hand, the maximal lipolytic
responses to post-adrenoceptor agents such as dibutyryl-cyclic AMP,
forskoline and theophylline, were lower in obese than in lean women,
in both adipose regions. Femoral fat cell lipolysis in the presence
of these agents was negatively correlated with body fatness indices.
These results suggest that, in women covering a wide range of
adiposity, variations in the lipolytic response of femoral fat cells
to epinephrine may involve changes in the functional balance between
[alpha]2-and [beta]-adrenoceptors, but also alterations located at
different post-receptor levels.
Received 1 July 1994; accepted in final form 23 March 1995.
APS Manuscript Number E245-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 4 April 1995.