Sertoli cell secreted growth factor. Cellular origin, paracrine and endocrine regulation of secretion

Rat and human Sertoli cells in culture secrete a growth factor, Sertoli cell secreted growth factor (SCSGF). The aims of the present study were (1) to evaluate other testicular cell types as additional sources of SCSGF, as well as their paracrine effect, and (2) to study the hormonal regulation of SCSGF secretion using an A431 cell growth assay. The Sertoli cell was the only testicular cell type tested that secreted SCSGF activity in vitro. Peritubular cells enhanced Sertoli cell attachment and SCSGF secretion. Spermatogenic cells had no effect. The secretion of SCSGF was specifically stimulated by follicle-stimulating hormone (FSH) and testosterone. Treatment with agents that increase intracellular cAMP levels and adenosine stimulated the secretion of mitogenic activity into Sertoli cell-conditioned medium by three- to fivefold. This growth factor, secreted by the Sertoli cell and regulated by FSH and testosterone, may play a critical role in the regulation of spermatogenesis.