THE CONTROL OF GONADOTROPIN-SECRETION BY OVARIAN-STEROIDS
THE CONTROL OF GONADOTROPIN-SECRETION BY OVARIAN-STEROIDS
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DOI：
10.1093/humrep/8.suppl_2.97
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发表时间：
1993-11-01
影响因子：
6.1
通讯作者：
SCHAISON, G
中科院分区：
文献类型：
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作者：
COUZINET, B;SCHAISON, G
卵巢类固醇在下丘脑和垂体前叶水平都发挥反馈作用，以调节促性腺激素的分泌。雌二醇降低编码促性腺激素α和β亚单位的mRNA的活性。在卵泡晚期，雌二醇对垂体黄体生成素（LH）的释放起正反馈控制作用，对卵泡刺激素（FSH）起负反馈控制作用。雌二醇还诱导促性腺激素释放激素（GnRH）分泌在排卵前增加，这种增加是持续的而非阵发性的。这种GnRH的升高可能并非产生LH峰所必需。孕酮主要在下丘脑水平发挥作用，通过诱导β -内啡肽的释放降低GnRH脉冲频率。然而，下丘脑并非孕酮作用的唯一靶点，因为它对促性腺激素释放的促进作用可能在垂体水平。这种正反馈作用在接受脉冲式GnRH治疗的下丘脑促性腺激素缺乏的女性中进行了研究。在生理剂量下，孕酮在垂体水平对LH分泌有刺激作用。最后，关于雄激素对促性腺激素分泌的影响，对10名正常月经周期的女性给予非甾体类纯抗雄激素（氟他胺）12个月，并未显著改变LH脉冲的平均水平、频率或幅度，以及LH和FSH对GnRH的反应性。雄激素（除了其芳香化为雌激素外）在正常女性的促性腺激素调节中不直接发挥生理作用。
Ovarian steroids exert feedback effects at the level of both the hypothalamus and anterior pituitary to regulate the secretion of gonadotrophins. Oestradiol decreases the activity of mRNA encoding the alpha and beta subunits of gonadotrophins. In the late follicular phase, oestradiol exerts a positive feedback control over pituitary lutenizing hormone (LH) release and a negative control over follicle stimulating hormone (FSH). Oestradiol also induces a pre-ovulatory increase of gonadotrophin releasing hormone (GnRH) secretion which is continuous rather than episodic. Such a GnRH rise may not be required to produce the LH surge. Progesterone exerts its major effect at the hypothalamic level and decreases GnRH pulse frequency by inducing the release of beta-endorphin. However, the hypothalamus is not the exclusive target of progesterone action, for its facilitatory action on gonadotrophin release may be at the level of the pituitary gland. This positive feedback effect was studied in women with hypothalamic gonadotrophin deficiency treated with pulsatile GnRH. In physiological doses, progesterone had a stimulatory effect on LH secretion at the pituitary level. Finally, regarding the effect of androgens upon gonadotrophin secretion, the administration of a non-steroidal pure anti-androgen (Flutamide) for 12 months in 10 normally cycling women did not change significantly the mean levels, frequency, or amplitude of LH pulses or the LH and FSH responsiveness to GnRH. Androgens (apart from their aromatization to oestrogens) do not directly play a physiological role in gonadotrophin regulation in normal women.