Russell L D, Saxena N K, Turner T T
Department of Physiology, School of Medicine, Southern Illinois University, Carbondale 62901-6512.
Tissue Cell. 1989;21(3):361-79. doi: 10.1016/0040-8166(89)90051-7.
The process of spermiation and sperm transport was studied using specific inhibitors of cytoskeletal elements. Within 12-24 hr after the intratesticular injection of taxol, a compound that acts to stabilize microtubules and inhibit microtubule-related processes, an unusually large number of microtubules was seen within the body of the Sertoli cell. At the same time, transport of elements within the seminiferous epithelium was affected. At the end of stage VI of the cycle, step 19 spermatids were maintained in the deep recesses of the Sertoli cell and not transported to the rim of the seminiferous tubule lumen. At stage VIII, residual bodies remained at, or near, the rim of the tubule and were not transported to the base of the tubule. They underwent only partial degradation at this site, indicating that there may have been two phases involved in their dissolution--one autophagic and one phagocytic, but the latter did not occur since the residual bodies were not transported to Sertoli lysosomes at the base of the tubule. The observations suggest that microtubules are involved in transport processes within the seminiferous epithelium. Within 1-12 hr after the intratesticular injection of 500 microM cytochalasin D, a compound which interferes with actin-related processes, normal appearing tubulobulbar complexes were not present. The tubular portion (distal tube) of the complex did not initiate development. It was assumed that filaments (which were identified as such using NBD-phallacidin and the S-1 fragment of myosin) played an important role in the development of this portion of the complex. Cells did not eliminate cytoplasm normally, as evidenced by an enlarged cytoplasmic droplet, further emphasizing the published role for tubulobulbar complexes in cytoplasmic elimination. Although sperm were released normally from stage VIII tubules, many remained within the tubular lumen and did not traverse the duct system. Cytochalasin did not inhibit fluid secretion by the Sertoli cell, as demonstrated by efferent duct ligation, but did alter myoid cell actin cytoskeletal organization, suggesting that myoid cell contractility is primarily responsible for transport of sperm. Overall, the observations suggest that cytoskeletal activity of the Sertoli cell is important for several aspects of the spermiation process as well as sperm transport.
利用细胞骨架成分的特异性抑制剂研究了精子释放和精子运输过程。在睾丸内注射紫杉醇（一种作用是稳定微管并抑制微管相关过程的化合物）后12 - 24小时内，在支持细胞体内可见数量异常多的微管。与此同时，生精上皮内成分的运输受到影响。在周期的VI期结束时，第19步的精子细胞被保留在支持细胞的深部凹陷处，未被运输到生精小管腔的边缘。在VIII期，残余体留在小管边缘或其附近，未被运输到小管基部。它们在该部位仅发生部分降解，这表明其溶解可能涉及两个阶段——一个自噬阶段和一个吞噬阶段，但由于残余体未被运输到小管基部的支持细胞溶酶体，吞噬阶段未发生。这些观察结果表明微管参与生精上皮内的运输过程。在睾丸内注射500微摩尔细胞松弛素D（一种干扰肌动蛋白相关过程的化合物）后1 - 12小时内，未出现正常形态的管球复合体。复合体的管状部分（远端管）未开始发育。据推测，细丝（使用NBD - 鬼笔环肽和肌球蛋白的S - 1片段鉴定为细丝）在复合体这一部分的发育中起重要作用。细胞不能正常清除细胞质，这通过增大的细胞质滴得以证明，进一步强调了管球复合体在细胞质清除中的已发表作用。尽管精子正常地从VIII期小管释放，但许多仍留在管腔内，未穿过管道系统。如通过输出小管结扎所证明的，细胞松弛素不抑制支持细胞的液体分泌，但确实改变了肌样细胞肌动蛋白细胞骨架的组织，这表明肌样细胞的收缩性主要负责精子的运输。总体而言，这些观察结果表明支持细胞的细胞骨架活性对于精子释放过程以及精子运输的几个方面都很重要。
