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Investigation of oocyte maturation inhibitory proteins from urine of pregnant women.

孕妇尿液中卵母细胞成熟抑制蛋白的研究。

基本信息

批准号：
02808028
负责人：
SAKAKIBARA Ryuzo
金额：
$ 0.96万
依托单位：
FAculty of Pharmaceutical Sciences, Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02808028/
关键词：
Mouse oocyte Oocyte maturation Nonsecretory ribonuclease Opioid peptide Urinary peptides from pregnant women Urinary peptides RNase

项目摘要

In mammals, the germinal vesicle of follicle-enclosed oocytes remains arrested at the dictyate stage of meiosis until the occurrence of a gonadotropin surge. Upon releasing the oocytes from the follicles in vitro, the meiotic process resumes, leading to a spontaneous germinal breakdown(GVBD)followed by the first polar body formation(PBF)of the oocytes, suggesting that oocyte maturation inhibitor(s)sustain the meiotic arrest of oocytes. In normal pregnancy, although hormonal levels of chorionic gonadotropin and estrogen are high, significant maturation of the oocytes and follicles do not occur for a long period, suggesting the possibility of a considerable increase in concentration of oocyte maturation inhibitor(s)in urine during pregnancy. The purpose of this study was to determine protein inhibitor(s)using denuded mouse oocytes in culture, if such inhibitor(s)are present in urine of pregnant women.The results obtained from this study are as follows :1. A protein inhibitor of PBF was purified from a uine of pregnant women by Sephadex G-100 and reversed-phase chromatographies. It was revealed that this protein possessed an ribonuclease activity and amino terminal sequence analysis showed that this protein is a product of a peculiar processing of a nonsecretory ribonuclease precursor. This protein was detected only in urine of pregnant women but not of normal men and women.2. A fraction with molecular mass of less than 2, 000 daltons containing peptide inhibitor(s)of GVBD was prepared by gel filtration from pregnancy urine. The inhibitory activity of this fraction was partially reversed in the presence of naloxon, a potent opioid antagonist. Activity of this fraction obtained from pregnancy urine was significantly potent than same fractions obtained from normal women and men.

在哺乳动物中，卵泡包围的卵母细胞的生殖囊泡在减数分裂的网状期保持停滞，直到促性腺激素峰的发生。在体外从卵泡释放卵母细胞后，减数分裂过程恢复，导致自发性胚泡破裂（GVBD），随后是卵母细胞的第一极体形成（PBF），这表明卵母细胞成熟抑制剂维持卵母细胞的减数分裂停滞。在正常妊娠中，尽管绒毛膜促性腺激素和雌激素的激素水平很高，但卵母细胞和卵泡的显著成熟不会在很长一段时间内发生，这表明妊娠期间尿液中卵母细胞成熟抑制剂浓度可能会显著增加。本研究的目的是利用培养的小鼠裸卵母细胞检测孕妇尿液中是否存在蛋白质抑制物。用SephadexG-100和反相层析从孕妇尿中分离纯化了一种PBF蛋白抑制剂。结果表明，这种蛋白质具有核糖核酸酶活性和氨基末端序列分析表明，这种蛋白质是一种非分泌核糖核酸酶前体的特殊加工的产物。该蛋白仅在孕妇尿中检出，而在正常男性和女性尿中均未检出.用凝胶过滤法从孕妇尿中分离出分子量小于2000道尔顿的GVBD多肽抑制剂组分。在纳洛酮（一种强效阿片类拮抗剂）存在下，该馏分的抑制活性部分逆转。从妊娠尿液中获得的该组分的活性显著强于从正常女性和男性中获得的相同组分。