In this study, we measured plasma concentrations of progesterone, pregnenolone, estradiol, estrone, estrone sulfate, and cortisol and analyzed the correlations between these hormones during gestation in 13 Suffolk ewes, the main breed in Japan. Progesterone increased during gestation and decreased a few days before parturition; however, this pattern was different in samples with high progesterone concentrations (P4 spike samples). This P4 spike was associated with a high pregnenolone concentration. Apart from the P4 spike, the progesterone change was similar to that in other sheep breeds. Pregnenolone increased during gestation and decreased after parturition. A significant correlation between progesterone and pregnenolone was observed a few days before parturition. Estrone sulfate and estradiol concentrations increased during gestation, but estrone did not. They increased shortly before parturition, and then decreased immediately after parturition. At parturition, the correlation between estrone and estrone sulfate was significantly stronger. Moreover, a strong correlation between estrone sulfate and estradiol was observed after parturition. Cortisol did not change during gestation and increased shortly before parturition. The results showed steroid hormone dynamics in normal pregnant Suffolk ewes, which were mostly in line with those of other sheep breeds. It should be noted that high progesterone concentrations altered the typical patterns.

中文翻译：

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萨福克母羊妊娠和分娩期间血浆类固醇激素的浓度及其关系。

在这项研究中，我们测量了日本主要品种萨福克（Suffolk）13头母羊在孕期的孕激素，孕烯醇酮，雌二醇，雌酮，硫酸雌酮和皮质醇的血浆浓度，并分析了这些激素之间的相关性。孕期孕酮增加，而在分娩前几天减少。但是，在高孕酮浓度的样品（P4加标样品）中，这种模式是不同的。P4峰值与孕烯醇酮浓度高有关。除了P4峰值外，孕酮的变化与其他绵羊品种中的相似。孕烯醇酮在妊娠期间增加，而在分娩后减少。分娩前几天，孕酮和孕烯醇酮之间存在显着相关性。妊娠期硫酸雌酮和雌二醇的浓度增加，但雌酮没有。它们在分娩前不久增加，然后在分娩后立即减少。在分娩时，雌酮和硫酸雌酮之间的相关性明显更强。此外，分娩后观察到硫酸雌酮和雌二醇之间的强相关性。皮质醇在妊娠过程中没有改变，在分娩前不久就增加了。结果显示正常的萨福克怀孕母羊中类固醇激素的动力学，与其他绵羊品种的雌激素激素动力学基本一致。应当指出，高黄体酮浓度改变了典型模式。分娩后观察到硫酸雌酮和雌二醇之间有很强的相关性。皮质醇在妊娠过程中没有改变，在分娩前不久就增加了。结果显示正常的萨福克怀孕母羊中类固醇激素的动力学，与其他绵羊品种的雌激素激素动力学基本一致。应当指出，高黄体酮浓度改变了典型模式。分娩后观察到硫酸雌酮和雌二醇之间有很强的相关性。皮质醇在妊娠过程中没有改变，在分娩前不久就增加了。结果显示正常的萨福克怀孕母羊中类固醇激素的动力学，与其他绵羊品种的雌激素激素动力学基本一致。应当指出，高黄体酮浓度改变了典型模式。