Seligman J, Kosower N S, Shalgi R
Department of Human Genetics, Sackler School of Medicine, Tel Aviv University, Israel.
Biol Reprod. 1992 Feb;46(2):301-8. doi: 10.1095/biolreprod46.2.301.
Mammalian spermatozoa mature while passing through the epididymis. Maturation is accompanied by thiol oxidation to disulfides. In rats, sperm become motile and fertile in the cauda. We have previously demonstrated that rat caput sperm contain mostly thiols and that upon passage from the corpus to the cauda epididymidis, sperm protein thiols are oxidized. The present work was undertaken to study the role of the regions of the epididymis in sperm maturation as reflected in the thiol status, fertility, and motility of the spermatozoa. The distal caput epididymidis of mature albino rats was ligated on one side. After 5 days, sperm were isolated from the ligated caput and from caput and cauda of the control side. Thiol groups in sperm, epididymal luminal fluid (EF), and epididymal tissue were labeled using the fluorescent thiol-labeling agent monobromobimane. After ligation, changes were observed in a) sperm proteins, sperm nuclear proteins, and epididymal fluid by electrophoresis; b) epididymal tissues by histochemistry; c) progressive motility by phase microscopy; and d) fertilizing ability after insemination into uteri of immature females. We found that after ligation, caput sperm thiols, especially protamine thiols, are oxidized, rendering them similar to mature sperm isolated from the cauda epididymidis. Spermatozoa from ligated caput epididymidis gain progressive motility and partial fertilizing ability. Morphology of epithelial cells of ligated caput is similar to that of cauda cells. However, other changes in caput EF and epithelium induced by ligation render the ligated caput epididymidis different from either control caput or cauda. Hence, sperm thiol oxidation, along with the development of fertilizing ability, can occur in sperm without necessity for sperm transit through the corpus and cauda epididymidis.
哺乳动物的精子在通过附睾时成熟。成熟过程伴随着硫醇氧化为二硫键。在大鼠中，精子在附睾尾部变得有活力且具备受精能力。我们之前已经证明，大鼠附睾头精子主要含有硫醇，并且当精子从附睾体进入附睾尾时，精子蛋白硫醇会被氧化。目前的研究旨在探讨附睾各区域在精子成熟过程中的作用，这可通过精子的硫醇状态、受精能力和运动能力来反映。将一侧成熟白化大鼠的附睾头远端进行结扎。5天后，从结扎侧的附睾头以及对照侧的附睾头和附睾尾分离精子。使用荧光硫醇标记剂单溴联苯胺标记精子、附睾管腔液（EF）和附睾组织中的硫醇基团。结扎后，通过以下方法观察变化：a）通过电泳观察精子蛋白、精子核蛋白和附睾液；b）通过组织化学观察附睾组织；c）通过相差显微镜观察精子的前向运动能力；d）将精子注入未成熟雌性大鼠子宫后观察受精能力。我们发现，结扎后，附睾头精子的硫醇，尤其是鱼精蛋白硫醇被氧化，使其类似于从附睾尾分离出的成熟精子。来自结扎附睾头的精子获得了前向运动能力和部分受精能力。结扎附睾头的上皮细胞形态与附睾尾细胞相似。然而，结扎诱导的附睾头EF和上皮细胞的其他变化使得结扎后的附睾头与对照附睾头或附睾尾均有所不同。因此，精子硫醇氧化以及受精能力的发展可以在精子中发生，而无需精子通过附睾体和附睾尾。
