title: Placental expression of nitric oxide synthase during HELLP syndrome: the correlation with maternal-fetal Doppler velocimetry.
abstract: BACKGROUND
  To correlate Doppler waveform of the uterine and umbilical vessels to placental nitric oxide synthase (NOS) expression in pregnant women with HELLP (hemolysis, elevated liver enzymes, low platelets count) syndrome.
  
  
  METHODS
  mRNA expression of inducible NOS (iNOS) and endothelial NOS (eNOS) was assessed, after cesarean section, in placental samples from 10 women affected by HELLP syndrome and 10 controls. Pulsatility indices on Doppler waveform analysis from uterine and umbilical arteries were measured.
  
  
  RESULTS
  iNOS expression was significantly lower in placenta from women with HELLP syndrome than controls. When comparing the results with Doppler flow measurements, we found a negative correlation between umbilical pulsatility index and eNOS expression (r = -0.91) and a positive correlation with iNOS expression (r = 0.86).
  
  
  CONCLUSIONS
  The reduced iNOS expression in women with HELLP syndrome may indicate the extreme placental dysfunction that is unable to compensate for the endothelial derangement and related hypertension in spite of trying to improve fetoplacental perfusion and the delivery of nutrients to the fetus.
authors.affiliation: Department of Obstetrics and Gynecology, Polytechnic University of Marche, Salesi Hospital via Corridoni 11, 60123 Ancona, Italy. tranquilli@univpm.it
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Tranquilli
authors.forename: Stefano R
authors.initials: SR
authors.lastname: Giannubilo
authors.forename: Elisa
authors.initials: E
authors.lastname: Tedeschi
authors.forename: Valeria
authors.initials: V
authors.lastname: Bezzeccheri
authors.forename: Hisanori
authors.initials: H
authors.lastname: Suzuki
authors.forename: Marta
authors.initials: M
authors.lastname: Menegazzi
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D042783:Endothelial Cells / Q000201:enzymology; D005260:Female; D017359:HELLP Syndrome / Q000201:enzymology* / Q000503:physiopathology; D006801:Humans; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011673:Pulsatile Flow / Q000502:physiology; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging*; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging
chemical_list: D019001:Nitric Oxide Synthase