Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Asian J Androl. 2011 Mar;13(2):275-80. doi: 10.1038/aja.2010.147. Epub 2010 Dec 20.
C-type natriuretic peptide (CNP) is a 22-amino acid peptide and act as a local paracrine or autocrine regulator. There is growing evidence that CNP is involved in male reproductive processes. To investigate the role of CNP during spermatogenesis, we measured the mRNA expression of CNP and its specific membrane-bound natriuretic peptide receptor-B (NPR-B) using real-time RT-PCR in the testes of normal rats on different postnatal days. After that spermatogenesis dysfunction model induced by ornidazole was established with the aim to study the correlation of CNP with spermatogenic dysfunction. Then, Sertoli cells from 18- to 22-day-old healthy male rats were cultured in the presence of different CNP concentrations (1×10(-6), 1×10(-7) and 1×10(-8) mol l(-1)), and the mRNA expression levels of androgen-binding protein, inhibin B and transferrin were examined at 0 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h and 48 h. During the postnatal development of rat testes, the highest mRNA expression levels of CNP and NPR-B were found at postnatal D(0), and the levels then declined gradually, with a second CNP peak at postnatal D(35). In the ornidazole-induced infertile rat testes, CNP gene expression was lower than in the uninduced rats (P<0.05), while NPR-B gene expression was greater (P<0.05). In cultured Sertoli cells, supplementation with CNP stimulated the gene expression of androgen-binding protein/inhibin B/transferrin, particularly at 12 h, and 1×10(-7) mol l(-1) CNP had the highest upregulation effect. The gene expression levels of CNP/NPR-B in rat testes at different postnatal stages and in infertile rat testes indicated that CNP may participate in the physiology and/or pathology related to spermatogenesis. Moreover, CNP regulated endocrine function in Sertoli cells. Taken together, these results showed that CNP is closely tied to spermatogenesis.
C 型利钠肽（CNP）是一种 22 个氨基酸肽，作为局部旁分泌或自分泌调节剂发挥作用。越来越多的证据表明 CNP 参与了男性生殖过程。为了研究 CNP 在精子发生中的作用，我们使用实时 RT-PCR 测量了正常大鼠不同出生后天数睾丸中 CNP 及其特异性膜结合利钠肽受体-B（NPR-B）的 mRNA 表达。之后，我们建立了奥硝唑诱导的生精功能障碍模型，旨在研究 CNP 与生精功能障碍的相关性。然后，我们将 18-22 日龄健康雄性大鼠的支持细胞在不同 CNP 浓度（1×10(-6)、1×10(-7)和 1×10(-8)mol l(-1))下培养，并在 0 分钟、30 分钟、1 小时、2 小时、4 小时、8 小时、12 小时、24 小时和 48 小时时检测雄激素结合蛋白、抑制素 B 和转铁蛋白的 mRNA 表达水平。在大鼠睾丸的出生后发育过程中，CNP 和 NPR-B 的 mRNA 表达水平在出生后第 0 天达到最高，然后逐渐下降，在第 35 天出现第二个 CNP 高峰。在奥硝唑诱导的不育大鼠睾丸中，CNP 基因表达低于未诱导大鼠（P<0.05），而 NPR-B 基因表达更高（P<0.05）。在培养的支持细胞中，CNP 补充刺激雄激素结合蛋白/抑制素 B/转铁蛋白的基因表达，特别是在 12 小时，1×10(-7)mol l(-1)CNP 具有最高的上调作用。不同出生后阶段大鼠睾丸和不育大鼠睾丸中 CNP/NPR-B 的基因表达水平表明，CNP 可能参与精子发生的生理和/或病理过程。此外，CNP 调节支持细胞的内分泌功能。总之，这些结果表明 CNP 与精子发生密切相关。
