Physiological levels of androstenedione reduce bone loss in
ovariectomized rats and this effect is mediated by androgens.
Lea, C. K., and A. M. Flanagan.
Department of Histopathology, Imperial College School of Medicine
at St. Mary's, London, UK
APStracts 4:0246E, 1997.
The effect of androstenedione (adione) slow-release pellets on
cancellous bone volume (BV/TV) at the tibial metaphysis was
investigated in ovariectomized (ovx) rats at various times from 21 to
180 days. Plasma levels of adione, testosterone (T) in the ovx rats
were significantly reduced at 21 days and were restored close to
levels in the sham rats with the 1.5 mg adione pellet. Ovx animals
with and without adione pellets resulted in close to a 50% reduction
in BV/TV by day 21. By day 180, the ovx rats had only 5% BV/TV
whereas that in the adione-treated ovx rats was significantly greater
at 12%. The reduced BV/TV was associated with increased bone
resorption and formation. In a separate 90 day experiment, we found
that the anti-androgen, Casodex, abrogated the adione-induced
skeletal-protective effect in the ovx rats, whereas the anti
-aromatase, Arimidex, had no effect. This provides evidence that
adione protects against the development of osteopenia in the
estrogen-deficient rat and mediates its effect through androgens and
not estrogens.
Received 27 March 1997; accepted in final form 31 October 1997.
APS Manuscript Number E1411-7.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 14 November 1997