Gallagher A C, Chambers T J, Tobias J H
Department of Histopathology, St. George's Hospital Medical School, London, United Kingdom.
Am J Physiol. 1996 Mar;270(3 Pt 1):E407-12. doi: 10.1152/ajpendo.1996.270.3.E407.
We investigated whether androgens, for which the ovaries are the major source in female rats, contribute to the stimulation of cancellous bone formation by ovarian hormones in female rats. Ovariectomized animals were administered 5alpha-dihydrotestosterone (DHT; 10 and 100 microgram/kg) by daily subcutaneous injection for 13 days, after which histomorphometric analysis was performed at the proximal tibial metaphysis. To prevent ovariectomy from stimulating bone turnover, and hence complicating the interpretation of changes in bone formation, animals were also given the resorption inhibitor 3-amino-1-hydroxypropylidene-1-bisphosphonate. We found that ovariectomy markedly suppressed cancellous bone formation, which was partially prevented by DHT (100 microgram/kg). To further address whether androgens contribute to the stimulation of bone formation by ovarian hormones, we treated intact and ovariectomized female rats with the androgen antagonist flutamide (15 mg/kg/day) for 28 days. Whereas flutamide had no effect in ovariectomized rats, it significantly reduced cancellous bone formation in intact animals. We conclude that, in the female rat, androgens contribute under physiological conditions to the stimulation of cancellous bone formation by ovarian hormones.
我们研究了雄激素（在雌性大鼠中卵巢是其主要来源）是否有助于雌性大鼠卵巢激素对松质骨形成的刺激作用。对去卵巢动物每日皮下注射5α-双氢睾酮（DHT；10和100微克/千克），持续13天，之后在近端胫骨干骺端进行组织形态计量学分析。为防止去卵巢刺激骨转换，从而使骨形成变化的解释复杂化，还给动物使用了吸收抑制剂3-氨基-1-羟基亚丙基-1-双膦酸盐。我们发现去卵巢显著抑制松质骨形成，DHT（100微克/千克）可部分预防这种抑制。为进一步探讨雄激素是否有助于卵巢激素对骨形成的刺激，我们用雄激素拮抗剂氟他胺（15毫克/千克/天）对完整和去卵巢的雌性大鼠进行了28天的处理。虽然氟他胺对去卵巢大鼠没有影响，但它显著降低了完整动物的松质骨形成。我们得出结论，在雌性大鼠中，雄激素在生理条件下有助于卵巢激素对松质骨形成的刺激。
