PROGESTIN ANTAGONISM OF ESTROGEN STIMULATED 1,25-DIHYDROXYVITAMIN-D LEVELS
PROGESTIN ANTAGONISM OF ESTROGEN STIMULATED 1,25-DIHYDROXYVITAMIN-D LEVELS
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DOI：
10.1210/jc.75.2.519
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发表时间：
1992-08-01
影响因子：
5.8
通讯作者：
PORTALE, AA
中科院分区：
文献类型：
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作者：
BIKLE, DD;HALLORAN, BP;PORTALE, AA
孕激素经常与雌激素联合使用，以预防或治疗绝经后骨质疏松症。孕激素可防止雌激素对子宫内膜的不良增生作用。孕激素可能拮抗雌激素对钙稳态的有益作用的可能性很少受到关注。在这项研究中，我们确定了在雌激素中加入雷公藤红素是否会改变雌激素提高血清1，25-二羟维生素D [1，25-（OH）2D]水平的能力。绝经5年内的妇女接受3个周期的口服非对抗性雌激素[每个周期1或2 mg/天（3.67或7.34 μ mol/天）17-β-雌二醇（E2）25/30天]，随后接受3个周期的E2加孕酮[10 mg/天（29 μ mol/天）甲羟孕酮，第12 - 251天。E2以剂量依赖性方式增加总的和游离的1，25-（OH）2D浓度。这些水平在三个周期的非对抗性雌激素治疗中逐渐增加。相反，维生素D结合蛋白浓度在一个E2周期后达到最大水平。在添加维生素D后，总的和游离的1，25-（OH）2D水平恢复到基线水平，尽管维生素D结合蛋白水平仍然升高。随着血清钙水平的下降，两种剂量的E2都使PTH水平升高。孕激素没有显着改变E2对PTH或钙的影响。我们的研究结果提出了一种可能性，即雷公藤红素可能拮抗雌激素对钙稳态的部分有益作用。
Progestins are frequently used in combination with estrogen to prevent or treat postmenopausal osteoporosis. Progestins protect against the undesirable hyperplastic effects of estrogen on the endometrium. The possibility that progestins might antagonize the beneficial effects of estrogen on calcium homeostasis has received little attention. In this study we determined whether the addition of progestin to estrogen would alter the ability of estrogen to raise serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] levels. Women within 5 yr of menopause were treated with three cycles of oral unopposed estrogen [1 or 2 mg/day (3.67 or 7.34-mu-mol/day) 17-beta-estradiol (E2) for 25/30 days of each cycle] followed by three cycles of E2 plus progestin [10 mg/day (29-mu-mol/day) medroxyprogesterone on days 12-251. E2 increased both total and free 1,25-(OH)2D concentrations in a dose-dependent fashion. These levels increased progressively over the three cycles of unopposed estrogen treatment. In contrast the vitamin D binding protein concentration reached maximal levels after one cycle of E2. With the addition of progestin, the levels of total and free 1,25-(OH)2D returned toward baseline although vitamin D binding protein levels remained elevated. PTH levels rose with both doses of E2 as serum calcium levels fell. Progestin did not significantly alter the effects of E2 on PTH or calcium. Our results raise the possibility that progestin may antagonize part of the salubrious effects of estrogen on calcium homeostasis.