OVARIAN STEROIDS AND CALCIUM HOMEOSTASIS

最近完成的工作绝经后妇女的初级 甲状旁腺机能亢进症表明，雌激素治疗不仅能够 阻断骨吸收，还能刺激PTH-1，25- (OH)2D轴，提高肠道钙吸收，从而改善钙质 平衡和骨密度。雌激素刺激的机制 肾脏1，25-(OH)2D的合成需要进一步阐明。此操作 雌激素的释放可能是由于对肾脏的直接影响，也可能是 继发性甲状旁腺功能亢进伴抑制 骨吸收，或者另一种可能性是雌激素可能增加 肾脏对甲状旁腺素的敏感性。为了解决这些问题， 雌激素对维生素D代谢和肠道功能的影响47例 甲状旁腺素缺乏的患者将进行吸收检查 甲状旁腺激素治疗前后甲状旁腺功能减退。 长期服用促性腺激素释放激素类似物亮丙瑞林已被证明可以 抑制促性腺激素和卵巢类固醇至去势水平。这 可逆式“医学卵巢切除术”可能对女性有益 患有子宫内膜异位症、子宫肌瘤、多毛症或乳腺癌。 然而，雌激素缺乏可能与负钙有关。 平衡和骨质流失。子宫内膜异位症患者的短期研究 或肌瘤将检查亮丙瑞林诱导的效果 低雌激素对钙动态平衡的影响，并检测其能力 醋酸甲羟孕酮、降钙素或消炎痛用于封骨 吸收和/或促进肠道钙吸收。在对女性的研究中 对多毛症或乳腺癌患者，长期内科治疗效果较好 使用亮丙瑞林的卵巢切除术将根据变化进行评估 钙稳态和骨密度。潜在的口语能力 避孕药(作为治疗多毛症的辅助药物)和 非类固醇雌激素拮抗剂他莫昔芬(作为一种辅助药物 治疗乳腺癌)，以保护骨骼将被评估。

Recently completed work postmenopausal women with primary hyperparathyroidism showed that estrogen therapy was not only able to block bone resorption, but also was able to stimulate the PTH-1,25- (OH)2D axis, raise intestinal Ca absorption and thereby improve Ca balance and bone density. The mechanism by which estrogen stimulates renal 1,25-(OH)2D synthesis requires further elucidation. This action of estrogen may be due to a direct effect on the kidney, or it may be mediated by secondary hyperparathyroidism accompanying the inhibition of bone resorption, or another possibility is that estrogen may increase renal sensitivity to PTH. To approach these questions, the effect of estrogens on vitamin D metabolism and fractional intestinal 47Ca absorption will be examined in patients with PTH-deficient hypoparathyroidism before and after the administration of PTH. Chronic administration of the GnRH analogue leuprolide has been shown to suppress gonadotropins and ovarian steroids to castrate levels. This type of reversible "medical oophorectomy" may be of benefit to women with endometriosis, uterine fibroids, hirsutism or breast cancer. However, estrogen deprivation may be associated witH negative calcium balance and bone loss. Short-term studies in women with endometriosis or fibroids will examine the effect of leuprolide-induced hypoestrogenism on Ca homeostasis, and test the ability of medroxyprogesterone acetate, calcitonin or indomethacin to block bone resorption and/or improve intestinal Ca absorption. In studies in women with hirsutism or breast cancer, the effect of more long-term medical oophorectomy with leuprolide will be evaluated with respect to changes in Ca homeostasis and bone density. The potential ability of oral contraceptives (as an adjunctive agent in treating hirsutism) and the nonsteroidal estrogen antagonist tamoxifen (as an adjunctive agent in treating breast cancer) to protect bone will be evaluated.