Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Laboratory of Animal Physiology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Gen Comp Endocrinol. 2020 Apr 1;289:113391. doi: 10.1016/j.ygcen.2020.113391. Epub 2020 Jan 7.
The aim of this study was to detect the seasonal expressions of oxytocin (OT), oxytocin receptor (OTR), extracellular signal-regulated kinase1 and 2 (ERK1/2) and phospho-ERK1/2 (pERK1/2) in the epididymis of the wild ground squirrels (Citellus Dauricus Brandt) during the breeding season and non-breeding season. Histological results showed that size, weight, cell number and lumen diameter of epididymis underwent acute seasonal changes, which were all peaked in the breeding season. Immunohistochemical results suggested that strong staining of OT, OTR, ERK1/2, and pERK1/2 were observed in the epithelial layer in the whole epididymis, along with intense OT and OTR signal in smooth muscle cell (Smc) in caudal epididymis in the breeding season. The protein expression levels of OTR, ERK1/2, and pERK1/2 in the epididymis were higher in the breeding season than those of the non-breeding season. Besides, hormone assay revealed that there was no significant serum concentration of OT in these two periods, while epididymal concentration showed higher value in the breeding season. In summary, the identified localization and local concentration of OT in the epididymis in the wild ground squirrel suggested that epididymis may assume as a source of OT, and OT could act via OTR to activate ERK1/2 signaling to regulate seasonal epididymal functions.
本研究旨在检测繁殖期和非繁殖期野生草原黄鼠（Citellus Dauricus Brandt）附睾中催产素（OT）、催产素受体（OTR）、细胞外信号调节激酶 1 和 2（ERK1/2）和磷酸化 ERK1/2（pERK1/2）的季节性表达。组织学结果表明，附睾的大小、重量、细胞数量和管腔直径在繁殖季节发生急剧季节性变化，在繁殖季节达到峰值。免疫组织化学结果表明，OT、OTR、ERK1/2 和 pERK1/2 在整个附睾上皮层均有强烈染色，在繁殖季节附睾尾部平滑肌细胞（Smc）中也有强烈的 OT 和 OTR 信号。繁殖季节附睾中 OTR、ERK1/2 和 pERK1/2 的蛋白表达水平均高于非繁殖季节。此外，激素检测显示这两个时期血清 OT 浓度没有显著差异，而附睾中的 OT 浓度在繁殖季节更高。总之，在野生草原黄鼠附睾中鉴定出 OT 的定位和局部浓度表明，附睾可能作为 OT 的来源，OT 可以通过 OTR 激活 ERK1/2 信号转导来调节季节性附睾功能。
