Progesterone and human chorionic gonadotropin do not stimulate placental proteins 12 and 14 or prolactin production by human decidual tissue in vitro.

To investigate the regulation of the synthesis and secretion of placental proteins-12 (PP12) and -14 (PP14) and PRL, explants and enriched preparations of stromal cells and gland cells obtained from 10 human early pregnancy decidua were preincubated in medium for 24 h (baseline), followed by incubation in medium with or without progesterone (0.02-32 mumol/L), hCG (10 and 100 ng/ml), or cAMP (0.25-1 mmol/L) in an atmosphere of 5% CO2-95% air at 37 C for another 96-120 h. Media were changed each 24 h, and PP12, PP14, and PRL levels were determined by RIA. Decidual explants, as well as their isolated cells produced detectable levels of PP12, PP14, and PRL in vitro. The gland cells synthesized and secreted about 30 times more PP14 than did stromal cells. After 96-120 h of incubation, the production of each protein by control cultures was increased 81-167% compared to the baseline (not significant). The secretion of these proteins in medium supplemented with progesterone or hCG was not significantly different from that in the control groups. 8-Bromo-cAMP significantly increased the secretion of PRL and PP12, but not PP14, by stromal cells compared to control values. We conclude that 1) PP14 is mainly produced by decidual gland cells; 2) progesterone at the concentrations used in our study does not stimulate production of PP12, PP14, and PRL in decidualized endometrium in vitro; 3) hCG does not stimulate the production of PP12 and PP14 in decidualized endometrium; and 4) 8-bromo-cAMP stimulates decidual stromal cell secretion of PRL and PP12.