Assinder S J, Carey M, Parkinson T, Nicholson H D
Department of Anatomy, University of Bristol, School of Veterinary Science, Bristol BS2 8EJ, United Kingdom.
Biol Reprod. 2000 Aug;63(2):448-56. doi: 10.1095/biolreprod63.2.448.
Contractions of seminiferous tubules and epididymal duct walls promote spermiation and sperm transfer, and they are thought to be stimulated by the related peptides oxytocin and vasopressin. This study tested the hypothesis that if oxytocin and/or vasopressin play a physiological role in sperm shedding and transport, then local or circulating concentrations of these peptides would increase during puberty. Testes, epididymides, and trunk blood of sheep at stages during the first spermatogenic wave were collected, and radioimmunoassay measured significant increases in testicular and epididymal oxytocin during spermatogenesis. No changes were measured in circulating oxytocin or in local or circulating vasopressin. Localization and synthesis was investigated by immunohistochemistry and Western blot analysis employing antibodies recognizing epitopes of either oxytocin, oxytocin-associated neurophysin, vasopressin, or vasopressin-associated neurophysin. Marked expression of both oxytocin and its associated neurophysin in testicular Leydig and epididymal principal cells was seen, and weak neurophysin immunoreactivity was also identified in Sertoli cells. The intercellular distribution of oxytocin varied between regions of the epididymis, suggesting several roles for oxytocin. Vasopressin synthesis was not apparent in either tissue. These results confirm the presence and development of paracrine oxytocinergic systems in the ram testis and epididymis of ram during puberty while questioning the physiological importance of vasopressin.
生精小管和附睾管壁的收缩促进精子释放和转运，据认为这是由相关肽类催产素和加压素刺激所致。本研究检验了这样一个假设：如果催产素和/或加压素在精子排出和运输过程中发挥生理作用，那么在青春期这些肽类的局部或循环浓度会升高。采集处于首次生精波各阶段的绵羊的睾丸、附睾和躯干血液，放射免疫分析测定出在精子发生过程中睾丸和附睾中的催产素显著增加。循环中的催产素以及局部或循环中的加压素均未测出有变化。通过免疫组织化学和蛋白质印迹分析，使用识别催产素、催产素相关神经垂体素、加压素或加压素相关神经垂体素表位的抗体来研究其定位和合成。在睾丸间质细胞和附睾主细胞中均可见到催产素及其相关神经垂体素的显著表达，在支持细胞中也鉴定出微弱的神经垂体素免疫反应性。附睾各区域间催产素的细胞间分布有所不同，提示催产素有多种作用。在这两种组织中均未明显见到加压素的合成。这些结果证实了青春期公羊睾丸和附睾中旁分泌催产素能系统的存在和发育，同时也对加压素的生理重要性提出了质疑。
