An intraovarian inhibitory action of estrogen on androgen production in vivo.
An intraovarian inhibitory action of estrogen on androgen production in vivo.
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雌激素对体内雄激素产生的卵巢内抑制作用。
DOI：
10.1095/biolreprod19.3.641
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发表时间：
1978
影响因子：
3.6
通讯作者：
D. Armstrong
中科院分区：
文献类型：
--
作者：
P. Leung;A. Goff;T. Kennedy;D. Armstrong
给未成熟雌性大鼠皮下注射雌二醇-17（1毫克）3天后，卵巢雄激素水平显著降低，从油处理大鼠卵巢组织的34±7 pg/mg降至13±2 pg/mg。它抑制卵巢对黄体生成素的反应，通过卵巢雄激素测定，但没有通过卵巢黄体酮浓度测定。在油处理的对照动物中，黄体生成素导致卵巢雄激素水平增加约5倍，而在雌激素处理的大鼠中，黄体生成素完全没有刺激卵巢雄激素水平。这种对卵巢雄激素反应的抑制作用在雌激素治疗6小时后也得到证实。对去垂体的未成熟大鼠连续3天给予雌二醇- 17美元，可抑制卵巢雄激素和黄体酮水平。完整和去垂体大鼠之间孕酮反应差异的原因尚不清楚。然而，就雄激素反应而言，雌激素的抑制作用不太可能是通过抑制内源性促性腺激素释放间接介导的，因为同时使用外源性促性腺激素未能改变雌激素的作用。相反，对卵巢的直接作用表明，单侧卵巢雌激素植入对同侧lh诱导的雄激素水平有抑制作用。但不对侧，卵巢在体内。这些结果表明，卵巢中存在一个局部的控制睾酮产生的负反馈回路，卵巢雌激素水平升高抑制卵巢对LH刺激的反应，从而降低睾酮的产生，进而降低雌激素的生物合成。
Subcutaneous administration of estradiol-17$ (I mg) to intact, immature female rats for 3 days significantly decreased ovarian androgen levels from 34 ± 7 pg/mg in oil treated control rats to 13± 2 pg/mg ovarian tissue. It inhibited ovarian responsiveness to LH, as measured by ovarian androgen, but not as measured by ovarian progesterone concentrations. In oil treated control animals, LH caused an approximately 5-fold increase in ovarian androgen levels, whereaa ovarian androgen levels were not stimulated at all by LH in the estrogen treated rats. This inhibitory effect on ovarian androgen response was also demonstrable after 6 h of estrogen treatment. Administration of estradiol-l7$ to hypophysectomized immature rats for 3 consecutive days suppressed both ovarian androgen and progesterone levels in response to LH. The cause of the discrepency in the progesterone response between intact and hypophyaectomized rats is not clear. However, with regard to the androgen response, it is unlikely that the inhibitory action of estrogen is indirectly mediated by a suppression of endogenous gonadotropin release, since concomitant administration of exogenous gonadotropins failed to alter the estrogen effect. Instead, a direct action on the ovary is suggested by the demonstration that unilateral ovarian estrogen implants exert an inhibitory effect on LH-induced androgen levels in the ipsilateral. but not contralateral, ovary in vivo. These results suggest that in the ovary there exists a local negative feedback loop for the control of testosterone production, in which elevated ovarian estrogen levels suppress ovarian responsiveness to LH stimulation, thereby lowering testosterone production and subsequently decreasing estrogen biosynthesis.