University Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
Nat Rev Urol. 2011 Apr;8(4):187-96. doi: 10.1038/nrurol.2011.23. Epub 2011 Mar 15.
Complete testicular descent is a sign of, and a prerequisite for, normal testicular function in adult life. The process of testis descent is dependent on gubernacular growth and reorganization, which is regulated by the Leydig cell hormones insulin-like peptide 3 (INSL3) and testosterone. Investigation of the role of INSL3 and its receptor, relaxin-family peptide receptor 2 (RXFP2), has contributed substantially to our understanding of the hormonal control of testicular descent. Cryptorchidism is a common congenital malformation, which is seen in 2-9% of newborn boys, and confers an increased risk of infertility and testicular cancer in adulthood. Although some cases of isolated cryptorchidism in humans can be ascribed to known genetic defects, such as mutations in INSL3 or RXFP2, the cause of cryptorchidism remains unknown in most patients. Several animal and human studies are currently underway to test the hypothesis that in utero factors, including environmental and maternal lifestyle factors, may be involved in the etiology of cryptorchidism. Overall, the etiology of isolated cryptorchidism seems to be complex and multifactorial, involving both genetic and nongenetic components.
睾丸完全下降是成年后睾丸正常功能的标志和前提。睾丸下降的过程依赖于系带的生长和重组，这受睾丸间质细胞激素胰岛素样肽 3（INSL3）和睾酮的调节。对 INSL3 及其受体松弛素家族肽受体 2（RXFP2）的作用的研究，极大地促进了我们对睾丸下降的激素控制的理解。隐睾症是一种常见的先天性畸形，在 2-9%的新生男婴中可见，成年后患不育症和睾丸癌的风险增加。尽管人类中一些孤立性隐睾症可以归因于已知的遗传缺陷，如 INSL3 或 RXFP2 突变，但大多数患者的隐睾症病因仍不清楚。目前正在进行一些动物和人类研究，以检验这样一种假设，即子宫内因素，包括环境和母体生活方式因素，可能参与隐睾症的病因。总体而言，孤立性隐睾症的病因似乎很复杂，涉及遗传和非遗传因素。
