Effect of danazol on gonadotropin and cAMP stimulated progesterone synthesis in cultured human granulosa cells

The effect of danazol on progesterone formation was studied in cultured human granulosa cells obtained from 20 follicles in the mid- to late follicular phase of normally menstruating women. The cells were cultured for 2 to 6 days in the presence of danazol (0.01 to 5 mg/l) alone and in combination with one of several progesterone stimulatory agents. The medium was changed every other day and analysed for progesterone with radioimmunoassay. In all cases progesterone synthesis was markedly stimulated by human FSH (10 micrograms/l), human LH (10-100 micrograms/l), hCG (1000 IU/l), forskolin (1 mumol/l) or 8-Bromo-cAMP (1 mmol/l). In the presence of danazol (1 mg/l) the FSH-, LH- and hCG-stimulated progesterone synthesis was partially inhibited by 55 to 60%. The response to forskolin or 8-Bromo-cAMP was also inhibited by danazol although to a somewhat lower extent (35 to 50%). Basal progesterone synthesis was inconsistently inhibited in some cases. It was concluded that not only gonadotropin-stimulated steroid synthesis, as previously demonstrated for hCG, but also forskolin and 8-Bromo-cAMP-stimulated steroidogenesis is sensitive to danazol inhibition. This suggests that the effect of danazol in human granulosa cells is due, at least partly, to interference with steps distal to cAMP generation.