Synthesis and secretion of prolactin in the decidualized human endometrium unassociated with pregnancy in vitro.

The effect of the decidualization induced by the administration of sex steroid hormones on the human endometrial PRL contents and the mechanism of synthesis and secretion of PRL in this decidualized endometrium of non-pregnant women were investigated. The PRL contents increased in proportion to the degree of decidualization. In vitro secretion of PRL in decidualized human endometrium was inhibited by the protein synthesis inhibitors, while TRH, dopamine, and bromocriptine did not have any effects on PRL secretion in incubation experiments. These data suggest that the production and secretion of PRL in the human endometrium have no relation to the presence of conceptus, and furthermore, they are regulated by mechanism different from the pituitary PRL.