title: Circulating calcitonin gene-related peptide and its placental origins in normotensive and preeclamptic pregnancies.
abstract: OBJECTIVE
  The present study was designed to determine plasma calcitonin gene-related peptide concentration in both maternal and fetal circulations in normotensive and pre-eclamptic pregnancies and investigate whether placenta is 1 of its origins.
  
  
  METHODS
  Maternal blood, cord blood, and villous tissue were collected from women in normotensive pregnancies and complicated with pre-eclampsia. Calcitonin gene-related peptide concentrations were determined by radioimmunoassay. Cellular localizations of calcitonin gene-related peptide messenger ribonucleic acid and protein expressions in placental villi were determined by in situ hybridization and immunohistochemistry.
  
  
  RESULTS
  The following results were reached: (1) maternal plasma calcitonin gene-related peptide concentrations increased with advancing gestation but fell after delivery; (2) both maternal and cord plasma calcitonin gene-related peptide concentrations were positively correlated with the infant birth weights; (3) compared with normotensive pregnancies, calcitonin gene-related peptide levels in both maternal and cord plasma decreased in pregnancies with pre-eclampsia; (4) in normotensive pregnancies, the plasma calcitonin gene-related peptide of the umbilical vein was higher than the umbilical artery, but no significant differences between vein and artery in pre-eclampsia; (5) calcitonin gene-related peptide messenger ribonucleic acid and protein were expressed by syncytiotrophoblast cells and villous vascular endothelial cells in normotensive pregnancies, but only weak or absent staining was observed in pre-eclamptic placentas; and (6) calcitonin gene-related peptide is secreted by villous tissue in explant culture in a time-dependent manner, but less calcitonin gene-related peptide was produced by villous tissues from patients with pre-eclampsia.
  
  
  CONCLUSIONS
  Calcitonin gene-related peptide may play potential roles in maternal hemodynamic adaptation and fetal growth. Decreased circulating calcitonin gene-related peptide levels may be involved in maternal-fetal pathophysiology of pre-eclampsia. It is novel that placenta villous tissues might be one of the potential sources of calcitonin gene-related peptide during pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Medical Branch, 301 University Boulevard, Room 11.138, Rt. 1062, Galveston, TX 77555-1062, USA. ydong@utmb.edu
authors.forename: Yuan-Lin
authors.initials: YL
authors.lastname: Dong
authors.forename: Madhu
authors.initials: M
authors.lastname: Chauhan
authors.forename: Kortney E
authors.initials: KE
authors.lastname: Green
authors.forename: Sujatha
authors.initials: S
authors.lastname: Vegiraju
authors.forename: Hui-Qun
authors.initials: HQ
authors.lastname: Wang
authors.forename: Gary D V
authors.initials: GD
authors.lastname: Hankins
authors.forename: Chandra
authors.initials: C
authors.lastname: Yallampalli
mesh_terms: D000328:Adult; D001158:Arteries; D001724:Birth Weight; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis / Q000097:blood* / Q000378:metabolism; D005260:Female; D005312:Fetal Blood; D005865:Gestational Age; D006801:Humans; D066298:In Vitro Techniques; D007231:Infant, Newborn; D009994:Osmolar Concentration; D010920:Placenta / Q000378:metabolism*; D049590:Postpartum Period / Q000097:blood; D011225:Pre-Eclampsia / Q000097:blood / Q000378:metabolism*; D011247:Pregnancy / Q000097:blood*; D014018:Tissue Distribution; D014470:Umbilical Cord / Q000098:blood supply; D014680:Veins
chemical_list: D015740:Calcitonin Gene-Related Peptide