Human placenta and fetal membranes express nerve growth factor mRNA and protein.

The present study investigated whether trophoblast, decidua and fetal membranes express nerve growth factor (NGF) mRNA and peptide. Tissue specimens were collected in the first and third trimester of pregnancy from women undergoing voluntary pregnancy interruption (no.= 6; from 8 to 12 gestational weeks) and from women having an elective caesarean section at term (no.= 6; week 39-40 of pregnancy). Using reverse transcriptase-polymerase chain reaction (RT-PCR), trophoblast, amnion/chorion and maternal decidua showed the expression of NGF mRNA both in early gestation and at term. By immunohistochemistry, the immunoreactive NGF was found in the cyto and syncytial trophoblast cells, chorionic mesodermic cells and in decidua. Vessel endothelial cells were stained in maternal compartments, while fetal vessels were unstained. These results, showing the expression and localization of NGF, support the current concept that human placenta is a potent neuroendocrine organ throughout gestation.