Zheng Lucheng, Su Juan, Fang Rui, Jin Mengmeng, Lei Zhihai, Hou Yuanlong, Ma Zhiyu, Guo Tingting
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Anim Reprod Sci. 2015 Mar;154:113-20. doi: 10.1016/j.anireprosci.2015.01.004. Epub 2015 Jan 24.
Gonadotropin-inhibitory hormone (GnIH), a key regulator of vertebrate reproduction, was identified in the Japanese quail in 2000, and RFamide-related peptide-3 (RFRP-3) was found to be a mammalian GnIH ortholog. To further determine its role in the reproductive system of male Xiaomeishan pigs, we systematically investigated changes in GnIH and its receptors (GPR147 and GPR74) during the development of the reproductive axis of male pigs. We also investigated the direct effect of RFRP-3 on the synthesis and secretion of testosterone in Leydig cells in vitro. The expression patterns of GnIH in the reproductive axis of male pigs at different stages of development (postnatal 3, 30, 60, 90, and 120D) were studied using semiquantitative RT-PCR and immunohistochemistry. Our results show that hypothalamic, pituitary and testicular levels of GnIH and its receptors mRNA significantly changed on postnatal day 30 and postnatal day 90. The immunoreactivities of the GnIH proteins were mainly localized to the spermatogenic cells, sustentacular cells and interstitial cells of the testis throughout sexual development. It was confirmed that different doses of GnIH/RFRP-3 inhibited the release and synthesis of testosterone, and impacted on the gene expression of 3β-hydroxysteroid dehydrogenase (3β-HSD) and P450, enzymes that play a key role in the synthesis of testosterone. Together, this research provides molecular and morphological data on the regulation of GnIH in the reproductive development of male pigs.
促性腺激素抑制激素（GnIH）是脊椎动物生殖的关键调节因子，于2000年在日本鹌鹑中被鉴定出来，并且发现RF酰胺相关肽-3（RFRP-3）是哺乳动物GnIH的直系同源物。为了进一步确定其在雄性小梅山猪生殖系统中的作用，我们系统地研究了雄性猪生殖轴发育过程中GnIH及其受体（GPR147和GPR74）的变化。我们还在体外研究了RFRP-3对睾丸间质细胞中睾酮合成和分泌的直接影响。使用半定量RT-PCR和免疫组织化学研究了雄性猪在不同发育阶段（出生后3、30、60、90和120天）生殖轴中GnIH的表达模式。我们的结果表明，GnIH及其受体mRNA的下丘脑、垂体和睾丸水平在出生后第30天和第90天有显著变化。在整个性发育过程中，GnIH蛋白的免疫反应性主要定位于睾丸的生精细胞、支持细胞和间质细胞。已证实不同剂量的GnIH/RFRP-3抑制睾酮的释放和合成，并影响在睾酮合成中起关键作用的3β-羟基类固醇脱氢酶（3β-HSD）和P450的基因表达。总之，本研究提供了关于GnIH在雄性猪生殖发育中调节作用的分子和形态学数据。
