Bergmann M, Kliesch S
Institute of Anatomy of the University, Münster, Germany.
Anat Embryol (Berl). 1994 Dec;190(6):515-20. doi: 10.1007/BF00190101.
Testicular biopsies of infertile patients are often characterized by a mixed atrophy, in which different types of spermatogenic lesions are found in adjacent tubules. In order to evaluate a possible involvement of the state of differentiation of the Sertoli cells, the distribution pattern of cytokeratin and vimentin intermediate filaments within the seminiferous epithelium of 228 biopsy specimens with normal spermatogenesis (n = 10), mixed atrophy (n = 206) or Sertoli Cell Only Syndrome (n = 12) were investigated by means of immunohistochemical techniques. Sertoli cells were regularly found to show vimentin expression in tubules with normal spermatogenesis as well as in tubules with any kind of spermatogenic impairment including SCO. Cytokeratin expression as a marker showing lack of differentiation was common in Sertoli cells of tubules with arrest of spermatogenesis at the level of spermatogonia, and was occasionally associated with arrest at the level of primary spermatocytes or with SCO. Ultrastructural examination of tubules with spermatogonial arrest revealed Sertoli cells with features of typical fetal or prepubertal Sertoli cells, such as round to ovoid nuclei without indentations, stacks of rough ER and spot desmosomes. These data suggest that spermatogenic arrest at the level of spermatogonia might be due to functional impairment of the associated Sertoli cells, which have maintained or regained an undifferentiated state and are not able to initiate or trigger the process of spermatogonial differentiation.
不育患者的睾丸活检通常表现为混合性萎缩，即在相邻的曲细精管中发现不同类型的生精病变。为了评估支持细胞分化状态可能的参与情况，采用免疫组织化学技术研究了228例活检标本（正常生精标本n = 10例、混合性萎缩标本n = 206例或唯支持细胞综合征标本n = 12例）曲细精管上皮内细胞角蛋白和波形蛋白中间丝的分布模式。在生精正常的曲细精管以及包括唯支持细胞综合征在内的任何类型生精功能受损的曲细精管中，均经常发现支持细胞表达波形蛋白。细胞角蛋白表达作为缺乏分化的标志物，在精子发生停滞于精原细胞水平的曲细精管的支持细胞中很常见，偶尔也与初级精母细胞水平的停滞或唯支持细胞综合征有关。对精原细胞停滞的曲细精管进行超微结构检查发现，支持细胞具有典型胎儿或青春期前支持细胞的特征，如圆形至卵圆形核无凹陷、粗面内质网堆叠和点状桥粒。这些数据表明，精子发生停滞于精原细胞水平可能是由于相关支持细胞的功能受损，这些支持细胞维持或恢复了未分化状态，无法启动或触发精原细胞分化过程。
