Behrman H R, Aten R F, Ireland J J, Milvae R A
Department of Obstetrics/Gynecology, Yale University School of Medicine, New Haven, CT 06510.
J Reprod Fertil Suppl. 1989;37:189-94.
A GnRH-like protein, detected with a receptor assay for GnRH in rat ovarian membranes, is present in ovarian extracts of the rat, human, cow and ewe at levels much higher than immunoreactive GnRH. This protein has been partly purified and characterized from bovine ovaries. Highest levels of this protein are found in granulosa cells, but substantial activity is present in luteal, thecal and stromal tissue. No detectable GnRH-like activity is found in follicular fluid, or in ovarian venous or jugular plasma. The GnRH-like protein is structurally and immunologically different from GnRH, but it competitively and reversibly inhibits binding of GnRH to high-affinity sites in rat ovarian membranes. The GnRH-like protein markedly inhibits the action of both LH and FSH in cultures of rat luteal and granulosa cells, respectively, to a much greater extent than GnRH. Co-elution of receptor-binding activity and antigonadotrophic activity occurs within and between several chromatography procedures, but the protein has not been completely purified. The presence of this antigonadotrophic GnRH-like protein in the ovaries of diverse species raises the possibility that it may represent a novel paracrine regulator of ovarian function.
一种用大鼠卵巢膜中促性腺激素释放激素（GnRH）受体检测法检测到的GnRH样蛋白，存在于大鼠、人类、牛和羊的卵巢提取物中，其含量远高于免疫反应性GnRH。这种蛋白已从牛卵巢中部分纯化并进行了特性鉴定。该蛋白在颗粒细胞中含量最高，但在黄体、卵泡膜和基质组织中也有相当的活性。在卵泡液、卵巢静脉或颈静脉血浆中未检测到可检测到的GnRH样活性。这种GnRH样蛋白在结构和免疫方面与GnRH不同，但它能竞争性、可逆性地抑制GnRH与大鼠卵巢膜中高亲和力位点的结合。这种GnRH样蛋白分别在大鼠黄体和颗粒细胞培养物中显著抑制促黄体生成素（LH）和促卵泡生成素（FSH）的作用，其程度远大于GnRH。在几种色谱分析程序内和程序之间，受体结合活性和抗促性腺激素活性共同洗脱，但该蛋白尚未完全纯化。不同物种卵巢中这种抗促性腺激素的GnRH样蛋白的存在，增加了它可能代表一种新型卵巢功能旁分泌调节因子的可能性。
