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首页> 外文期刊>Physiological Reports >Local production of neurostradiol affects gonadotropin?￠????releasing hormone (GnRH) secretion at mid?￠????gestation in Lagostomus maximus (Rodentia, Caviomorpha)
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Local production of neurostradiol affects gonadotropin?￠????releasing hormone (GnRH) secretion at mid?￠????gestation in Lagostomus maximus (Rodentia, Caviomorpha)

机译：神经性雌二醇的局部产生会影响最大腹泻肌（Rodentia，Caviomorpha）孕中期促性腺激素释放激素（GnRH）的分泌。

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摘要

Females of the South American plains vizcacha, Lagostomus maximus , show peculiar reproductive features such as massive polyovulation up to 800 oocytes per estrous cycle and an ovulatory process around mid?￠????gestation arising from the reactivation of the hypothalamic?￠????hypophyseal?￠????ovary (H.H.O.) axis. Estradiol (E 2 ) regulates gonadotropin?￠????releasing hormone (GnRH) expression. Biosynthesis of estrogens results from the aromatization of androgens by aromatase, which mainly occurs in the gonads, but has also been described in the hypothalamus. The recently described correlation between GnRH and ER ???± expression patterns in the hypothalamus of the vizcacha during pregnancy, with coexpression in the same neurons of the medial preoptic area, suggests that hypothalamic synthesis of E 2 may affect GnRH neurons and contribute with systemic E 2 to modulate GnRH delivery during the gestation. To elucidate this hypothesis, hypothalamic expression and the action of aromatase on GnRH release were evaluated in female vizcachas throughout pregnancy. Aromatase and GnRH expression was increased significantly in mid?￠????pregnant and term?￠????pregnant vizcachas compared to early?￠????pregnant and nonpregnant females. In addition, aromatase and GnRH were colocalized in neurons of the medial preoptic area of the hypothalamus throughout gestation. The blockage of the negative feedback of E 2 induced by the inhibition of aromatase resulted in a significant increment of GnRH?￠????secreted mass by hypothalamic explants. E 2 produced in the same neurons as GnRH may drive intracellular E 2 to higher levels than those obtained from systemic circulation alone. This may trigger for a prompt GnRH availability enabling H.H.O. activity at mid?￠????gestation with ovulation and formation of accessory corpora lutea with steroidogenic activity that produce the necessary progesterone to maintain gestation to term and guarantee the reproductive success.
机译：南美平原比斯卡恰的雌性动物表现出独特的生殖特征，例如每个发情周期大量多卵泡多达800个卵母细胞，并且由于下丘脑重新激活而引起的妊娠中期排卵。垂体后叶（HHO）轴。雌二醇（E 2）调节促性腺激素释放激素（GnRH）的表达。雌激素的生物合成是由芳香酶将雄激素芳香化而产生的，芳香化主要发生在性腺中，但在下丘脑中也有描述。最近描述的妊娠期间，即在前视神经区的同一神经元中共表达GzRH的下丘脑下丘脑GnRH和ER±表达模式之间的相关性，表明下丘脑的E 2合成可能影响GnRH神经元并有助于全身性E 2在妊娠期间调节GnRH的传递。为了阐明这一假说，在整个怀孕过程中，对雌性比卡奇犬进行了下丘脑表达和芳香化酶对GnRH释放的作用的评估。与早期和非妊娠女性相比，在妊娠中期和足月妊娠粘液中芳香酶和GnRH的表达显着增加。此外，在整个妊娠过程中，芳香化酶和GnRH在下丘脑视前内侧神经元中共定位。由抑制芳香化酶引起的E 2负反馈的阻滞导致下丘脑外植体分泌的GnRHα-β-分泌物显着增加。与单独的全身循环获得的E 2相比，在与GnRH相同的神经元中产生的E 2可能将细胞内E 2驱动到更高的水平。这可能会触发GnRH即时可用性，从而启用H.H.O。排卵期中的活性，并形成具有类固醇生成活性的黄褐附体，产生必要的孕激素以维持妊娠至足月并保证生殖成功。

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