Direct effects of bromocriptine on the steroidogenic capability of porcine granulosa cells.

The direct effects of bromocriptine on steroidogenesis were examined in cultured porcine granulosa cells. The following observations were made with bromocriptine: (1) It significantly increased the basal or FSH-stimulated secretion of progesterone in cultured porcine granulosa cells at concentrations exceeding 10(-7) mol/l; (2) its inhibitory effect on basal estradiol secretion was demonstrated; (3) it did not influence cell number in cultured porcine granulosa cells; (4) it increased the extracellular accumulation of cAMP in a concentration-dependent manner; and (5) it did not induce a change in cytosolic free Ca2+ concentration. These findings suggest that bromocriptine exerts a direct effect on steroidogenesis in ovarian granulosa cells.