Cortisol stimulation of estradiol and progesterone secretion by human granulosa cells is independent of follicle-stimulating hormone effects.

The effects of cortisol on steroid secretion by human luteinized granulosa cells was investigated by culturing cells from mature follicles of gonadotropin-treated women. After culturing for 24 hours in medium containing 10% fetal bovine serum, the cells were washed and incubated in a chemically defined medium. Cortisol (10(-5), 10(-6), and 10(-7) M), follicle-stimulating hormone (FSH; 100 ng/ml), FSH plus cortisol (10(-6], or vehicle were added to replicate cultures. After incubating for 6 hours, medium was harvested and assayed for estradiol (E2) and progesterone (P). Cortisol (10(-5), 10(-6) but not 10(-7) M) significantly (P less than 0.05) stimulated E2 secretion when compared to controls. FSH alone did not alter E2 secretion while FSH plus cortisol had a similar effect to cortisol alone. Likewise, P secretion was significantly (P less than 0.05) increased by cortisol when compared with controls and the stimulation was dose dependent. FSH also stimulated P secretion, but the combination of FSH and cortisol did not give an additive or synergistic effect. It appears that cortisol can stimulate the secretion of E2 and P by human granulosa cells without involving FSH receptor interaction. The findings suggest that, in addition to pituitary and ovarian hormones, cortisol may also be directly involved in granulosa cell function.