J. Lopez-marti et al., Oleoyl-estrone induces the massive loss of body weight in Zucker fa/fa rats fed a high-energy hyperlipidic diet, J NUTR BIOC, 11(11-12), 2000, pp. 530-535
To rest whether oleoyl-estrone plus a hyperlipidic diet affects body weight
in Zucker fa/fa rats, 13-week-old male Zucker obese (fa/fa) rats initially
weighing 440-470 g were used. They were fed for 15 days with a powdered hy
perlipidic diet (16.97 MJ/kg metabolizable energy) in which 46.6% was lipid
-derived and 16.1% was protein-derived energy and containing 1.23 +/- 0.39
mu mol/kg of fatty-acyl esters of estrone. This diet was supplemented with
added oleoyl-estrone to produce a diet with 33.3 (mu mol/kg of fatty-acyl e
strone. Oral administration of oleoyl-estrone in a hyperlipidic diet (at a
mean dose of 0.5 mu mol.kg(-1).d(-1)) resulted in significant losses of fat
, energy and, ultimately, weight. Treatment induced the maintenance of ener
gy expenditure combined with lower food intake, creating an energy gap that
was filled with internal fat stores while preserving body protein, in cont
rast with the marked growth of controls fed the hyperlipidic diet. Treatmen
t of genetically obese rats with a hyperlipidic diet containing additional
oleoyl-estrone resulted in the loss of fat reserves with scant modification
of other metabolic parameters, except for lower plasma glucose and insulin
levels. The results agree with the postulated role of oleoyl-estrone as a
ponderostat signal. (C) Elsevier Science Inc. 2000. All rights reserved.