Prostaglandins (PGs) play a pivotal role in uterine reproductive process including maternal recognition of pregnancy, cell proliferation, and myometrium contractions in mammals. In this study, we investigated the immunolocalizations and expression levels of Prostaglandin E2 synthases cyclo-oxygenase (COX)-1 and COX-2, as well as one of PGE2 receptor subtypes 4 (EP4) in the uteri of the wild Daurian ground squirrels (Spermophilus dauricus) during the breeding and non-breeding seasons. Histologically, the thickness of endometrium: myometrium ratio in the uteri of the breeding season was higher than that of the non-breeding season. The immunostainings of COX-1, COX-2 and EP4 were observed in stromal cells, glandular cells and myometrium cells in the breeding and non-breeding seasons. The protein and mRNA expression levels of COX-1, COX-2 and EP4 were higher in the uteri of the breeding season than those of in the non-breeding season. The mean mRNA levels of COX-1, COX-2 and EP4 were positively correlated with uterine weights. In addition, the PGE2 concentration of uterine tissues as well as plasma PGE2, 17β-estradiol, progesterone, LH and FSH levels were also significantly higher in the breeding season compared to those of the non-breeding season. These results suggested that PGE2 might play an important autocrine or paracrine role in the regulation of seasonal changes in the uterine functions of the wild Daurian ground squirrels during the breeding and non-breeding seasons.

中文翻译：

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在野生达乌尔地松鼠（Spermophilus dauricus）子宫中，COX-1，COX-2和EP4的季节性表达。

前列腺素（PG）在子宫生殖过程中起着关键作用，包括母亲对哺乳动物的妊娠，细胞增殖和子宫肌层收缩的认识。在这项研究中，我们调查了野生达乌尔地松鼠子宫中前列腺素E2合酶环加氧酶（COX）-1和COX-2以及PGE2受体亚型4（EP4）之一的免疫定位和表达水平。育种和非育种季节中的Spermophilus dauricus。从组织学上讲，繁殖季节子宫内膜的厚度：子宫内膜的比率高于非繁殖季节的子宫。在繁殖和非繁殖季节，在基质细胞，腺细胞和子宫肌层细胞中观察到了COX-1，COX-2和EP4的免疫染色。COX-1的蛋白质和mRNA表达水平，在繁殖季节的子宫中，COX-2和EP4高于非繁殖季节的子宫。COX-1，COX-2和EP4的平均mRNA水平与子宫重量呈正相关。另外，与非繁殖季节相比，繁殖季节子宫组织中PGE2的浓度以及血浆PGE2、17β-雌二醇，孕酮，LH和FSH的水平也显着升高。这些结果表明，在繁殖和非繁殖季节，PGE2可能在调节野生达乌尔地松鼠子宫功能的季节性变化中起重要的自分泌或旁分泌作用。与非繁殖季节相比，繁殖季节子宫组织中PGE2的浓度以及血浆PGE2、17β-雌二醇，孕酮，LH和FSH的水平也显着升高。这些结果表明，在繁殖和非繁殖季节，PGE2可能在调节野生达乌尔地松鼠子宫功能的季节性变化中起重要的自分泌或旁分泌作用。与非繁殖季节相比，繁殖季节子宫组织中PGE2的浓度以及血浆PGE2、17β-雌二醇，孕酮，LH和FSH的水平也显着升高。这些结果表明，在繁殖和非繁殖季节，PGE2可能在调节野生达乌尔地松鼠子宫功能的季节性变化中起重要的自分泌或旁分泌作用。