Bioassayable Gonadotropin Releasing Hormone-Like Activity in the Spent Nutrient Medium of Rat Sertoli Cells in Primary Cultures

Abstract

Investigations were undertaken to demonstrate bioassayable GnRH-like activity in the spent nutrient medium of Sertoli Cells in Primary Cell Cultures (SCCM) using an in vitro bioassay procedure. The bioassay involved the use of intact pituitaries from day-12 male rats. Amounts of LH and FSH released into the incubation medium in response to varying doses of synthetic GnRH were measured by radioimmunoassays. SCCM was extracted with methanol and diethylether. The extracted SCCM was evaporated under a stream of nitrogen at 50°C. The dry residue was resuspended in the assay medium and centrifuged. The supernatant was used as the source of GnRH-like activity. The treated SCCM gave a dose response parallel to that given by synthetic GnRH. Boiling and trypsinization of extracted SCCM destroyed the GnRH-like activity. Addition of synthetic GnRH to different doses of extracted SCCM gave additive response.