Interactions of Sertoli Cells with Myoid Cells in vitro

Abstract

Preparations of Sertoli cells and peritubular myoid cells from testes of 20-day-old rats were cultured alone or together, and cellular interactions were assessed. In the co-cultured system, Sertoli cells within plaques became elevated, forming macroscopically visible mounds and protrusions. The morphologic characteristics of these structures were determined with scanning and transmission electron microscopy. The formation of a limiting membrane observed between individual Sertoli cell nodules and surrounding myoid cells resembled some aspects of the morphology of seminiferous tubules. Long-term co-cultures of Sertoli cells and myoid cells, stimulated by follicle stimulating hormone (FSH), continued to secrete androgen binding protein (ABP) under conditions in which Sertoli cell monocultures ceased production of ABP. The specificity of these cellular interactions was investigated. Bladder smooth muscle cells could substitute for peritubular myoid cells in eliciting mound formation of co-cultured Sertoli cells, but embryonic fibroblasts could not. However, embryonic fibroblasts, which did not secrete ABP, permitted FSH-stimulated Sertoli cells in long-term co-culture to maintain ABP production. In contrast, fibroblasts from the tunica albuginea, when co-cultured with Sertoli cells, neither elicited mound formation nor supported ABP production. We conclude that while unique specificity of cellular interactions between Sertoli cells and peritubular myoid cells is not apparent in cultured preparations from testes of 20-day-old rats, these cells do retain some of the properties required for aggregation and tubule formation characteristic of tubule morphogenesis.