title: Stem villous arteries from the placentas of heavy smokers: functional and mechanical properties.
abstract: OBJECTIVE
  The aim of the study was to compare the mechanical and functional properties of isolated small stem villous arteries from the placentas of women who smoked heavily (>/=15 cigarettes/d) during pregnancy with those from the placentas of nonsmokers.
  
  
  METHODS
  Isolated stem villous arteries were mounted in small-vessel myographs. Circumference-tension relationships were established with 124 mmol/L potassium chloride. Concentration-response curves were obtained for endothelin 1, prostaglandin F2alpha, vasoactive intestinal peptide, corticotropin-releasing hormone, sodium nitroprusside, and cadmium chloride. The effect of nitric oxide was examined with N omega-nitro-l -arginine.
  
  
  RESULTS
  Stem villous arteries from the heavy smoking group developed a significantly lower tension than did those from nonsmokers at 6 of 9 steps of the circumference-tension experiment (P <.05). Endothelin 1 evoked a significantly greater maximum vasoconstrictive response in stem villous arteries from heavy smokers than in those from nonsmokers (P <.05).
  
  
  CONCLUSIONS
  Stem villous arteries of heavy smokers have altered mechanical properties and a greater vasoconstrictive response to endothelin 1 than do those from nonsmokers. These changes may compromise fetal placental blood flow and thereby contribute to the lower birth weights seen among infants born to heavy smokers.
authors.affiliation: Department of Obstetrics and Gynecology, Hvidovre University Hospital, and the Department of Obstetrics and Gynecology, Holbaek County Hospital, Denmark.
authors.forename: H V
authors.initials: HV
authors.lastname: Clausen
authors.forename: J C
authors.initials: JC
authors.lastname: Jorgensen
authors.forename: B
authors.initials: B
authors.lastname: Ottesen
mesh_terms: D001158:Arteries / Q000033:anatomy & histology / Q000502:physiology*; D001696:Biomechanical Phenomena; D019256:Cadmium Chloride / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D015237:Dinoprost / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology; D010920:Placenta / Q000098:blood supply*; D011189:Potassium Chloride / Q000494:pharmacology; D011247:Pregnancy; D012907:Smoking / Q000009:adverse effects*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects