DEVELOPMENT OF A SENSITIVE PORCINE GRANULOSA-CELL BIOASSAY FOR FOLLICLE-STIMULATING-HORMONE (FSH)

Purpose: Our objective was to develop a sensitive in vitro bioassay fo r follicle-stimulating hormone (FSH) that does not require the housing of animals in a research facility. Materials and Methods: Porcine gra nulosa cells from 1- to 3-mm follicles were cultured on laminin for 48 hr in serum-free medium in the absence or presence of FSH or with oth er purified pituitary hormones, supplemented with 19-OH androstenedion e. Estradiol accumulation in medium per microgram of DNA of cells was determined as a reflection of FSH-induced aromatase activity. Results: FSH (0.01-10 ng/ml) caused a dose-dependent increase in estradiol pro duction per microgram of DNA, with 1, 10, and 100 ng/ml significantly higher than control. Porcine FSH was approximately two fold more biopo tent than rat FSH in this system. Higher doses of FSH (100 ng/ml) caus ed less estradiol accumulation, presumably reflecting FSH receptor dow n regulation. No other pituitary hormone produced significant estradio l accumulation. Unextracted serum from a patient with premature ovaria n failure (10-50 mu l) was tested in parallel to purified rat FSH (0-5 0 ng/ml) in this system, resulting in similar estradiol accumulation p er microgram of DNA. Conclusions: We have developed a porcine granulos a cell bioassay for FSH which is sensitive, is specific for FSH, and d oes not require the housing of animals on site. It can be completed by a technician within 4 working days and can detect FSH in a sample of human serum.