Effect of corticosteroids and progesterone on adrenomedullin output and expression in human fetal membranes and placenta trophoblasts

OBJECTIVE: Plasma adrenomedullin (AM) concentrations are increased in fetal and maternal circulation in response to exogenous glucocorticoids administration. The role of corticosteroids and progesterone in regulating AM synthesis and secretion was investigated in amnion and chorion trophoblast cells of the fetal membranes and in placental trophoblast cells. STUDY DESIGN: Cells were treated with betamethasone, hydrocortisone, and progesterone. Changes in AM output were measured with radioimmunoassay. Protein expression was evaluated with Western blot and immunohistochemistry. RESULTS: Betamethasone stimulated AM secretion and protein expression in placental trophoblast cells and in amnion cells of the fetal membranes. Hydrocortisone and progesterone did not induce any effect either on secretion or protein expression in placenta and fetal membranes cells. CONCLUSION: Glucocorticoids regulate AM secretion and expression by human placenta thereby promoting increased AM concentration in maternal and fetal circulation in circumstances characterized by increased cortisol levels