Placental urocortin-2 and -3: Endocrine or Paracrine Functioning During Healthy Pregnancy?

Placentas of healthy pregnant women do not, or not to any great extent, secrete urocortin-2 and -3 in the plasma. We show that urocortins can regulate the estradiol secretion from placental tissue cultures via the CRF-R2 mediated pathway. Therefore, placental urocortin-2 and -3 peptides are more likely to function as auto/paracrine messengers during healthy pregnancy, than as endocrine messengers.