The selective estrogen receptor modulator tamoxifen was administered to intact and
castrated male mice, and its effects on tibial bones and circulatory calcium, phosphate
and testosterone were compared with controls and castrated animals. Tamoxifen in a
dose used in humans for treatment of breast cancer decreased the weight of seminal
vesicles, an organ which is highly sensitive to the androgenic effect, decreased the
concentration of testosterone, but did not have any negative effect on bone density
or mineral content in intact mice. When castrated mice with extraordinarily low concentrations
of testosterone and weights of seminal vesicles were treated with tamoxifen, the changes
in bone density and bone mineral resulting from castration were not only entirely
prevented, but increased above the values of intact mice. At the same time, cortical
bone was lost in orchidectomized mice, and this decrease in cortical thickness of
femur was completely prevented by tamoxifen treatment. Pharmacological therapy with
estrogen agonist on bone, tamoxifen in androgen deficient adult male mice prevents
bone loss.
Key words
Tamoxifen - Male Mice - Orchidectomy - Bone Density - Bone Mineral Content - Cortical
Width
