生殖医学杂志2011，Vol.20Issue(z1)：3-7,5.DOI:10.3969/j.issn.1004-3845.2011.z1.002
促性腺激素释放激素激动剂降调对垂体内外的影响
The effect of gonadotropin-releasing hormone agonist-induced down-regulation on pituitary and ovarian function
朱桂金 1徐蓓 1聂睿1
作者信息
- 1. 华中科技大学同济医学院附属同济医院生殖中心,武汉430030
- 折叠
摘要
Abstract
Downregulation means regulating ovarian responsivity to hormone through the downregulation of hormone receptors, which is one of the mechanism of gonadotropins regulating its own function. Except for upregulation and downregulation of the receptors, autoregulation could also be realized by autocrine, paracrine secretion and hormone heterogeneity. The achievement of downregulation is through three pathways: decoupling of receptor and regulatory subunit Oprotein; receptor internalization; the regulation of c-AMP and decoupling of catalytic subunit.40%-60% of follicle-stimulating hormone (FSH) secretion is repressed by the immediate action of downregulation,while 90% luteinizing hormone (LH) could be repressed, so downregulation is used to prevent the premature LH surges. Regulation of paracrine secretion by downregulation requires the involvement of FSH and LH and regulatory factors of paracrine secretion have no effect on the promotion of follicular development. The negative feedback of steroid hormone is through the level of hypothalamus and pituitary, while downregulation functions at the level of the gonadotropin-releasing hormone (GnRH) receptors, so the normal positive and negative feedbacks are cancelled by downregulation.There exist GnRH receptors in granulosa cells, theca cells and luteal cells, so it could be presumed theoretically that GnRH may have direct effects on ovary. Both animal experiments and in vitro studiessuggest that GnRH may have a direct action on ovarian granulosa cells through interfering steroid synthesis and follicular development. So except for preventing the premature LH surges and decreasing the detrimental effect of high LH, the effect of GnRH agonist-induced down-regulation increasing pregnancy rate may be also through the immediate action on follicular development, oocyte maturation and endometrial receptivity, but no confirmation has been made by the existing evidence.关键词
促性腺激素释放激素激动剂/降调/垂体/卵巢Key words
Gonadotropin- releasing hormone agonist/ Downregulationj Pituitary/ Ovary引用本文复制引用
朱桂金,徐蓓,聂睿..促性腺激素释放激素激动剂降调对垂体内外的影响[J].生殖医学杂志,2011,20(z1):3-7,5.
