Effects of 17ß-estradiol and isoflavones on movement drive, body weight, and bone density in ovariectomised female rats

HERTRAMPF T.; ABDEL A.K.R.; DEGEN G. H.; DI VIRGILIO A.L.; LAUDENBACH-LESCHOWSKY U.; DIEL P.

Muenster, Alemania

Simposio; 49 Simposio del Deutschen Gesellschaft für Endokrinologie (DGE).; 2005

Reduced estrogen levels occurring during menopause in woman are accompanied by a variety of disorders, e.g. hot flushes, depressions, osteoporosis, increase of body weight, and reduced movement drive. In this study we investigated combined effects of physical activity, estradiol substitution, and a phytoestrogen rich diet on bone mineral density, increase of body weight, and movement drive in an animal model. Ovariectomized (OVX) female Wistar rats were either fed with an isoflavone rich diet (IRD) or substituted with estradiol (E2), for 3 months. Sham operated rats and vehicle treated OVX animals served as controls. One half of the animals had the opportunity of voluntary wheel running. OVX rats displayed eight times lower movement activity than Sham animals. E2 treatment, but not IRD, significantly increased the movement activity of OVX rats. During 3 months the lowest increase of body weight was observed in Sham animals, the highest rate in OVX animals. Apart from running activity E2 treatment, but not IRD, also lowered the increase of body weight significantly compared to OVX animals. Bone mineral density in the trabecular area of the tibia was strongly reduced in OVX rats compared to Sham animals. In contrast to IRD, E2 substitution resulted in a protection of bone density in this area compared to OVX animals. Our data demonstrate that body weight, movement drive, and bone density are positively influenced by E2. E2 acts in the trabecular area of the tibia in a bone-protective manner, increases movement drive and antagonizes the increase of body weight. All these effects could not be observed in animals fed an isoflavone rich diet.