Leydig cell and extracellular matrix effects on Sertoli cell function: biochemical and morphologic studies

The reciprocal influence between Leydig and Sertoli cells prepared from pig testis were studied by coculture of both types of cells in either plastic dishes or dishes coated with basement membrane matrix. After 2–3 days in plastic dishes, Sertoli cells produced an increase in the steroidogenic response of Leydig cells to hCG. Pretreatment of the coculture with pFSH enhanced the steroidogenic capacity of Leydig cells and increased the number of hCG receptors. Similarly, the number of FSH binding sites and the FSH‐induced plasminogen activator activity secretion of Sertoli cells cocultured with Leydig cells were increased. Pretreatment of the coculture with hCG further enhanced both parameters. The positive reciprocal trophic effects between Leydig cells and Sertoli cells were significantly enhanced when the coculture was carried out on the top of extracellular matrix. In addition, when cells were cocultured under these conditions, but not on plastic dishes, they were organized in cell clusters or island structures, with most of the Leydig cells located in the outer area, whereas Sertoli cells were located inside the islands.