A cell culture assay for follicle-stimulating hormone

Cultured rat ovarian granulosa cells respond to follicle-stimulating hormone (FSH) by synthesizing and secreting plasminogen activator. The specificity of the response for FSH prompted us to explore the use of this system as an in vitro bioassay for FSH. The release of FSH by pituitary cell cultures has been examined by this method, as have been preparations of FSH of known biological activity. The results indicate that the granulosa cell system allows accurate, rapid, and convenient determinations of FSH activity. Furthermore, the method obviates metabolic clearance problems associated with whole animal assays and it is extremely sensitive: as little as 10(-15) mol (approximately 100 micronIU) of FSH can be detected.