CASODEX (A NONSTEROIDAL ANTIANDROGEN) REDUCES CANCELLOUS, ENDOSTEAL, AND PERIOSTEAL BONE-FORMATION IN ESTROGEN-REPLETE FEMALE RATS

Testosterone has been implicated in the preservation of the skeleton i n women and female rats. In this study we investigated the role of and rogens in estrogen-replete female rats by giving Casodex (pure nonster oidal anti-androgen) daily and analyzing the effects on the skeleton u sing static and dynamic histomorphometric parameters after 3 weeks. Th ere was a significant reduction in the bone formation rate in both the cancellous bone of the tibial metaphysis and in the periosteal and co rticoendosteal diaphyseal bone (90%, 30%, and 100% reduction, respecti vely, compared with control animals, which was unaccompanied by a chan ge in the indices of bone resorption. Casodex had no effect on cancell ous bone volume and cortical bone area but this can be accounted for b y the short duration of the experiment. The serum levels of dehydroepi androsteronesulfate and androstenedione were significantly reduced in the Casodex-treated rats compared with the control animals and there w as no difference in the plasma levels of estrone, estradiol, or testos terone between the two groups. This study demonstrate that androgens p lay a physiological role in regulating osteoblast activity in female r ats.