The aim of this study was to evaluate the effects of estradiol ± different progestogens on body weight in ovariectomised mature female hooded-Lister rats.
35 rats were ovariectomised under anaesthesia; following a recovery period animals were divided into 2 groups namely: (1) intermittent hormone dosing weeks 16 and 1318, with no treatment weeks 712 and (2) delayed (no treatment in weeks 112) hormone treatment dosing weeks 1318. The hormone regimens included vehicle (v) (1 ml/kg olive oil), 17-β-estradiol propionate (E) only (450 μg/kg weekly) and E (450 μg/kg weekly) plus medroxyprogesterone 17-acetate or d (-)-norgestrel (MPA or NOR 15 mg/kg every 2nd week). Body weights for each animal were recorded and analysed with one-way ANOVA with post-hoc Dunnetts t-test, n=5.
Vehicle animals gained weight throughout the study. Hormone treatment attenuated the observed weight gain, with differences being more significant for group 1 animals.
|(Week) V||E (1)||E+MPA (1)||E+NOR (1)||E (2)||E+MPA (2)||E+NOR (2)|
|(*P<0.05, **P<0.01 and ***P<0.001 Dunnetts t-test).|
The findings of this study point to a beneficial effect of exogenous hormones on body weight. Group 1 animals showed significant reductions in body weight when compared to vehicle animals, this being most evident in the E only group. Group 2 animals do show reductions in body weight although these reductions were less significant. In group 1 the progestogenic agent attenuated the effects of the estradiol alone but this was not seen in the group 2 animals.
06 - 07 Nov 2006
Society for Endocrinology