Danazol stimulates the release of follicle-stimulating hormone and inhibits the release of prolactin in vitro studies on rat pituitary cell cultures.

The actions of danazol on the release of gonadotropins and prolactin (PRL) were investigated by using a culture of rat anterior pituitary gland cells. The addition of danazol in the range between 10(-9) M and 10(-5) M elevated the levels of follicle-stimulating hormone (FSH) in a dose-dependent manner. Danazol at 10(-5) M caused a 70% increase in FSH levels over the control. The intracellular contents of FSH was also increased by danazol, suggesting its stimulatory effect on both the synthesis and release of FSH. Danazol had no effect on the release of luteinizing hormone (LH). Danazol diminished the sensitivity of gonadotrophs to luteinizing hormone-releasing hormone (LHRH) in that the LHRH-induced release of both FSH and LH was suppressed. The amount of PRL released into medium was decreased by danazol in a dose-dependent way.