title: Immunohistochemical localization of endothelin-1 in placenta and fetal membranes in term and preterm human pregnancy.
abstract: OBJECTIVE
  The aim of the study was to determine the ET-1 localization on human placenta and fetal membranes and to compare its distribution between term and preterm pregnancies in laboring and non-laboring tissues.
  
  
  METHODS
  Tissues obtained from nine term elective cesarean section, eight spontaneous vaginal term delivery, and 13 preterm delivery from both cesarean section (N = 6) and vaginal delivery (N = 7) were studied by immunohistochemistry.
  
  
  RESULTS
  Immunoreactive ET-1 (IR-ET-1) was detected in villous and nonvillous trophoblast in all groups, although laboring tissues showed strong staining in the syncytiotrophoblast of the villi. ET-1 immunostaining of endothelial cells was observed in all placental villous vessels with a considerable variability within groups. In the fetal membranes, intensive immunopositive staining was observed in the chorionic trophoblast following vaginal deliveries in term and preterm tissues.
  
  
  CONCLUSIONS
  This is the first study to report the localization of IR-ET-1 in human fetal membranes and placenta, and suggests that amnion and trophoblast represents a source of ET-1 production or, alternatively, a site for ET-1 binding.
authors.affiliation: 2nd Department of Obstetrics and Gynecology, University La Sapienza, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Marinoni
authors.forename: A
authors.initials: A
authors.lastname: Picca
authors.forename: L
authors.initials: L
authors.lastname: Scucchi
authors.forename: E V
authors.initials: EV
authors.lastname: Cosmi
authors.forename: R
authors.initials: R
authors.lastname: Di Iorio
mesh_terms: D016232:Endothelins / Q000032:analysis*; D005321:Extraembryonic Membranes / Q000737:chemistry*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007743:Labor, Obstetric / Q000378:metabolism*; D007752:Obstetric Labor, Premature / Q000378:metabolism*; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy
chemical_list: D016232:Endothelins