[Modulation of prolactin (PRL) secretion in human uterine decidual cells at early pregnancy].

Decidualization is essential for implantation of embryo and maintenance of pregnancy in human. The mechanism of decidualization was investigated in this study by regulation of prolactin (PRL) release in cultured human decidual cells during first trimester of gestation. Progesterone significantly stimulated PRL secretion, but the effect of estrogen depended on its concentration, which was ineffective at the physiological level (10( 9) mol/L) but suppressed the stimulatory effect of progesterone at higher levels. Thus adequate proportion of estrogen and progesterone is important for the decidualization. Furthermore, RU486 dramatically inhibited PRL release, suggesting that the effect of progesterone was mediated, at least in part, through its receptor. cAMP at concentration higher than 10( 5) mol/L significantly increased PRL secretion, suggesting that the cAMP signal pathway might be involved in decidualization.