Liu Q, Xie W, Xiao Y, Gao F, Gao Q, Zhang H, Han Y, Yuan Z, Weng Q
College of Biological Science and Technology, Beijing Forestry University, Beijing, 100083, China.
College of Biological Science and Technology, Beijing Forestry University, Beijing, 100083, China.
Theriogenology. 2019 Jan 15;124:24-31. doi: 10.1016/j.theriogenology.2018.10.009. Epub 2018 Oct 9.
Oxytocin (OT) is presented in the male reproductive tract and has various physiological functions, such as stimulating contraction of the reproductive tract and aiding sperm transport. In this study we investigated seasonal expressions of OT and oxytocin receptor (OTR) in the epididymis of the muskrat during the breeding and non-breeding seasons. Morphologically, the weight and length of epididymis in the breeding season were significantly higher than those in the non-breeding season. In the breeding season, the lumen diameter and epithelial thickness of epididymis increased significantly, and there were a large number of sperms in the lumen. However, in the non-breeding season, the diameter of the lumen became significantly narrower, the epithelial height became thinner, and there was no sperm in the lumen. Immunohistochemical results showed that OT and OTR were presented in the cytoplasm of epithelial cells and smooth muscle cells within the epididymis, and the immunostainings of OT and OTR in the breeding season were significantly stronger compared with the non-breeding. In consistent with the immunohistochemical results, the mRNA levels of OT and OTR were higher in the whole epididymis during the breeding season than those in the non-breeding season. In addition, the concentrations of OT in the epididymis and sera were both significantly higher in the breeding season when compared to the non-breeding season. These results suggested that the epididymis of the muskrat was the direct target organ of OT, and OT might play a regulatory role in the epididymal function via endocrine or autocrine/paracrine manners.
催产素（OT）存在于雄性生殖道中，并具有多种生理功能，如刺激生殖道收缩和辅助精子运输。在本研究中，我们调查了麝鼠附睾在繁殖季节和非繁殖季节中OT和催产素受体（OTR）的季节性表达。形态学上，繁殖季节附睾的重量和长度显著高于非繁殖季节。在繁殖季节，附睾的管腔直径和上皮厚度显著增加，管腔内有大量精子。然而，在非繁殖季节，管腔直径显著变窄，上皮高度变薄，管腔内无精子。免疫组织化学结果显示，OT和OTR存在于附睾内上皮细胞和平滑肌细胞的细胞质中，与非繁殖季节相比，繁殖季节OT和OTR的免疫染色显著更强。与免疫组织化学结果一致，繁殖季节整个附睾中OT和OTR的mRNA水平高于非繁殖季节。此外，与非繁殖季节相比，繁殖季节附睾和血清中OT的浓度均显著更高。这些结果表明，麝鼠的附睾是OT的直接靶器官，OT可能通过内分泌或自分泌/旁分泌方式对附睾功能发挥调节作用。
