5 alpha-Dihydrotestosterone partially restores cancellous bone volume in osteopenic ovariectomized rats.
Although androgens are thought to be important for skeletal maintenance in females and males, little is known about the mechanisms involved. To investigate this question further, we examined the effects of administering 0.01, 0.1, or 1.0 mg/kg 5 alpha-dihydrotestosterone (DHT) for 60 days on the skeleton of ovariectomized rats. Treatment was delayed until 90 days after ovariectomy to enable bone loss to stabilize. We found that ovariectomy markedly reduced cancellous bone volume of the proximal tibial metaphysis due to a combination of loss and thinning of trabeculae. Cancellous bone volume was partially restored by all doses of DHT, with trabecular thickness, but not number, returning to that of sham-operated animals. DHT also stimulated longitudinal bone growth and endosteal and periosteal bone formation and suppressed histomorphometric indexes of cancellous bone resorption. This suggests that DHT influences skeletal metabolism in osteopenic ovariectomized rats both by stimulating bone formation and suppressing resorption, although it is unclear which, if any, of these actions predominate at cancellous sites.
Tobias
J H
JH
Department of Histopathology, St. George's Hospital Medical School, London, United Kingdom.
Gallagher
A
A
Chambers
T J
TJ
D000818:Animals; D001846:Bone Development / Q000187:drug effects*; D001851:Bone Diseases, Metabolic / Q000503:physiopathology*; D001862:Bone Resorption / Q000517:prevention & control; D013196:Dihydrotestosterone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar
D013196:Dihydrotestosterone