Tres L L, Smith E P, Van Wyk J J, Kierszenbaum A L
Exp Cell Res. 1986 Jan;162(1):33-50. doi: 10.1016/0014-4827(86)90424-6.
Sertoli-spermatogenic cell co-cultures prepared from sexually immature rats (20-22 days old) and maintained in serum-free, hormone/growth factor-supplemented medium were used to determine the cell-specific localization of the growth factor somatomedin-C (SM-C). SM-C localization studies were carried out by indirect immunofluorescence using a monoclonal antibody (sm-1.2) to SM-C. In cultured rat hepatocytes, Sertoli and testicular peritubular cells, SM-C immunoreactivity was observed as a diffuse distribution of discrete immunofluorescent granules. Radio-immunoassay experiments using a rabbit antibody against human SM-C showed that testicular peritubular cells and Sertoli cells in primary culture accumulated SM-C in the medium. In spermatogenic cells co-cultured with subjacent Sertoli cells, immunoreactive SM-C was associated with pachytene spermatocytes but not with spermatogonia or early meiotic prophase spermatocytes (leptotene or zygotene). Both Sertoli cells and pachytene spermatocytes displayed binding sites for exogenously added SM-C. SM-C6 binding to spermatocytes reaching an advanced stage of meiotic prophase suggests a possible role of this growth factor in the meiotic process.
从性未成熟大鼠（20 - 22日龄）制备并培养于无血清、添加激素/生长因子培养基中的支持细胞 - 生精细胞共培养物，用于确定生长因子生长调节素C（SM - C）的细胞特异性定位。使用抗SM - C的单克隆抗体（sm - 1.2）通过间接免疫荧光进行SM - C定位研究。在培养的大鼠肝细胞、支持细胞和睾丸管周细胞中，SM - C免疫反应性表现为离散免疫荧光颗粒的弥漫性分布。使用抗人SM - C的兔抗体进行的放射免疫测定实验表明，原代培养中的睾丸管周细胞和支持细胞在培养基中积累了SM - C。在与下层支持细胞共培养的生精细胞中，免疫反应性SM - C与粗线期精母细胞相关，但与精原细胞或减数分裂前期早期精母细胞（细线期或偶线期）无关。支持细胞和粗线期精母细胞均显示对外源添加的SM - C有结合位点。SM - C与进入减数分裂前期晚期的精母细胞结合表明该生长因子在减数分裂过程中可能发挥作用。
