title: Effects of L-arginine on utero-placental circulation in growth-retarded fetuses.
abstract: BACKGROUND
  To evaluate the effects of L-arginine (ARG) infusion, the nitric oxide as substrate, on the utero-placental circulation at third trimester.
  
  
  METHODS
  Three groups of nine pregnant women each were infused i.v. with 30 g ARG, for 30 minutes. One group served as control, and the two remnants were composed by patients with intrauterine growth retardation with (IUGR-B) or without (IUGR-A) increased resistances in the utero-placental circulation. Changes of blood flow velocity waveforms of both uterine arteries and umbilical artery were recorded for 60 minutes. Blood pressure, serum nitrites/nitrates and growth hormone levels were also measured.
  
  
  RESULTS
  No hemodynamic changes in utero-umbilical circulation were observed during infusion in any of the three groups. Considering the uterine arteries separately as placental and non-placental sided we found a significant decrease of non-placental side resistances in IUGR-B women. Indeed, the pulsatility index was lowered by 14%, in respect of baseline value. Serum nitrites/nitrates as well as serum growth hormone levels were significantly increased by ARG, in every woman, irrespective of the presence of fetal growth retardation. Blood pressure remained unaffected during infusion in every woman.
  
  
  CONCLUSIONS
  These findings suggest that L-arginine infusion affects utero-placental circulation in patients with IUGR associated with increased uterine resistances. Such an action is specific and appears possibly to be mediated by a release of nitric oxide.
authors.affiliation: Department of Obstetrics and Gynecology, Medical School, University of Modena, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Neri
authors.forename: V
authors.initials: V
authors.lastname: Mazza
authors.forename: M C
authors.initials: MC
authors.lastname: Galassi
authors.forename: A
authors.initials: A
authors.lastname: Volpe
authors.forename: F
authors.initials: F
authors.lastname: Facchinetti
mesh_terms: D000328:Adult; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood; D006801:Humans; D007263:Infusions, Parenteral; D008423:Maternal Age; D018377:Neurotransmitter Agents / Q000378:metabolism; D017942:Nitric Acid / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000097:blood; D010298:Parity; D021041:Placental Circulation / Q000187:drug effects*; D011247:Pregnancy
chemical_list: D018377:Neurotransmitter Agents; D009573:Nitrites; D009569:Nitric Oxide; D017942:Nitric Acid; D001120:Arginine