[Effects of bromocriptine on FSH and LH secretion in women with euprolactinemic anovulation (author's transl)].

A few reports have been given that Bromocriptine effected not only on the hyperprolactinemic anovulations but also on the euprolactinemic anovulations. This study was performed to examine the underlying mechanism, 5 mg of Bromocriptine was daily administered for 30 days to 38 women with euprolactinemic anovulations. The basal secretions of FSH, LH and Prolactin and also the responsiveness to LH-RH, TRH and estradiol were examined. 31.6% of oligomenorrhea, anovulatory cycle and Ist. grade amenorrhea showed ovulatory cycles, however, no ovulations were observed in IInd. grade amenorrhea. The basal levels of FSH and LH significantly increased but the basal levels of Prolactin decreased by Bromocriptine. The responsiveness of FSH to LH-RH was markedly promoted but LH showed no significant change. Serum FSH was suppressed in estrogen loading test after Bromocriptine, which was poorly changed before. On the other hand, serum LH was markedly elevated by estradiol after Bromocriptine, which showed poor elevation before. These results conclude that: 1) Ovulation is induced by Bromocriptine administration in euprolactinemic anovulations. 2) Bromocriptine promotes the FSH and LH secretion from the pituitary and also promotes the reserve of FSH in the pituitary. 3) Bromocriptine promotes the sensitivity of the estrogen feedback in the hypothalamus.