Jezek D, Hittmair A, Rogatsch H, Kos M
Institute of Histology and Embryology, Zagreb Medical School, Croatia.
Anat Embryol (Berl). 1996 Feb;193(2):181-90. doi: 10.1007/BF00214709.
Testicular peritubular cells are located in the lamina propria of seminiferous tubules. These cells, significantly contributing to the basal membrane of seminiferous epithelium, have been studied in a number of species. However, there is a lack of data on the development of the lamina propria in the human testis. The aim of our survey was to investigate the characteristics of the lamina propria and, in particular, peritubular cells in the fetal human testes by immunohistological and stereological methods. Therefore, testes (14-39 weeks of gestation, n = 45) were dissected and fixed in a 4% buffered paraformaldehyde solution. Several pieces of each testis were embedded in paraffin and processed for immunohistochemical and stereological analysis. All investigated testes have shown sex cords in the process of development and differentiation. Morphologically, peritubular cells in the lamina propria can be divided into two types: fibroblast-like (FL) and myoid-like (ML) type (cells which much resemble mature myoid cells). By immunohistochemistry, both FL and ML cells are found to be strongly positive for the intermediate filament desmin, but negative for alpha-smooth actin. While FL cells intensively express Ki-67 demonstrating proliferative activity, ML cells are found to be negative. The basement membrane of sex cords as well as the blood vessels of the interstitium show strong positivity to collagen IV and laminin. Concerning the correlation between the appearance of the investigated antigens with the gestational age, all antigens have been expressed (in the manner described above) already in the 14th week of gestation. The stereological analysis of the number (Nv) and volume (Vv) of peritubular cells indicates a pulsatile development of these cells in the lamina propria of the human fetal testis. While the stereological variables determined for FL cells show a gradual decrease, the same variables determined for ML cells demonstrate a successive increase. It appears that the lamina propria of the fetal human testes shares many of the properties previously discovered in rodents.
睾丸生精小管周细胞位于生精小管的固有层。这些细胞对生精上皮的基底膜有重要贡献，已在多个物种中得到研究。然而，关于人类睾丸固有层发育的数据匮乏。我们此次调查的目的是通过免疫组织学和体视学方法研究人类胎儿睾丸固有层的特征，特别是生精小管周细胞的特征。因此，我们解剖了妊娠14 - 39周的睾丸（n = 45），并将其固定在4%的缓冲多聚甲醛溶液中。每个睾丸取数块组织包埋于石蜡中，进行免疫组织化学和体视学分析。所有研究的睾丸均显示出性索处于发育和分化过程中。形态学上，固有层中的生精小管周细胞可分为两种类型：成纤维细胞样（FL）和类肌样（ML）型（与成熟肌样细胞非常相似的细胞）。通过免疫组织化学发现，FL细胞和ML细胞对中间丝结蛋白均呈强阳性，但对α - 平滑肌肌动蛋白呈阴性。虽然FL细胞强烈表达Ki - 67，显示出增殖活性，但ML细胞呈阴性。性索的基底膜以及间质中的血管对IV型胶原和层粘连蛋白呈强阳性。关于所研究抗原的出现与胎龄之间的相关性，所有抗原在妊娠第14周时就已（以上述方式）表达。对生精小管周细胞数量（Nv）和体积（Vv）的体视学分析表明，这些细胞在人类胎儿睾丸固有层中呈脉动式发育。虽然为FL细胞确定的体视学变量显示逐渐减少，但为ML细胞确定的相同变量则显示出连续增加。看来人类胎儿睾丸的固有层具有许多先前在啮齿动物中发现的特性。
