Site-related white adipose tissue lipid-handling response to oleoyl-estrone treatment in overweight male rats.
BACKGROUND
Oleoyl-estrone (OE) decreases energy intake while maintaining glucose homeostasis, and energy expenditure at the expense of body fat. White adipose tissue (WAT) depots behave differently under starvation, postprandial state and pharmacologically induced lipolysis.


OBJECTIVE
To understand the mechanism of massive lipid loss from WAT elicited by OE treatment.


METHODS
We used overweight male rats. Rats receiving OE (10 nmol/g) gavages were compared with controls and a pair-fed group. Whole fat pads from the mesenteric, retroperitoneal, epididymal and inguinal subcutaneous sites were excised and analyzed for lipid, DNA, mRNA and the expression of lipogenic, fatty acid transporters and lipase genes.


RESULTS
In OE and pair-fed rats, WAT weights decreased, with the limited loss of cells. Patterns of gene expression in most WAT sites were similar for OE and PF, suggesting a shared mechanism of fat mobilization, but in mesenteric WAT, PF increased lipogenic and fatty acid transporter gene expressions. However, OE inhibited lipogenic expressions more deeply than PF.


CONCLUSIONS
White adipose tissue sites showed different expression patterns, hinting at relatively specialized functions in fat storage; thus, single site analyses cannot be extrapolated to whole WAT. Differences between mesenteric and the other sites suggest that 'visceral fat' should be reserved for this site only, and not applied to other abdominal fat depots (epididymal, retroperitoneal).
del Mar Romero
María
M
Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Barcelona, Spain. marromero@ub.edu
Fernández-López
José Antonio
JA
Esteve
Montserrat
M
Alemany
Marià
M