Effect of bromocriptine (CB-154) on oestrogen-induced prolactin release

In order to study the interaction between oestrogens and bromocriptine on PRL release, we evaluated the ability of bromocriptine (CB-154) to counteract the oestrogen-induced PRL release in four hyperprolactinaemic amenorrhoeic women. Bromocriptine acutely administered induced a similar percentage of PRL decrease in the same patient before and after oestrogen administration. When bromocriptine was chronically administered, contemporary oestrogen injection did not affect PRL release. These results show that bromocriptine is able to block the release of PRL induced by oestrogens, suggesting an interaction between oestrogens and DA-mimetic compounds on PRL release.