title: Influence of gestational age on the vasodilatory response of serotonin in human umbilical arteries perfused in vitro.
abstract: BACKGROUND
  Serotonin (5-hydroxytryptamine) is a potent vasoactive substance in human umbilical arteries (HUA).
  
  
  OBJECTIVE
  To investigate the vasodilatory response pattern of serotonin in HUA from pregnancies complicated by preterm deliveries as compared to uncomplicated term pregnancies.
  
  
  METHODS
  Umbilical cord segments were perfused in vitro. These were taken from pregnancies complicated by preterm delivery before 34 weeks' gestation (group 1, n = 8), between 34 and 37 weeks' gestation (group 2, n = 7), and uncomplicated term pregnancies (group 3, n = 17). All women were normotensive and without proteinuria, and showed no signs of infection.
  
  
  RESULTS
  Serotonin induced monophasic vasoconstrictory responses or biphasic responses with a transient vasodilation succeeded by a vasoconstriction. The frequency of preparations displaying a biphasic response increased with gestational age. The frequencies were 1/8, 3/7 and 12/17 in groups 1, 2 and 3, respectively (p = 0.023). The correlation between the maximum dilatory response obtained in each preparation and gestational age was positive and significant (r = 0.49, p = 0.004). No significant differences were observed in the constrictory responses between the groups.
  
  
  CONCLUSIONS
  In in vitro perfused HUA, the vasodilatory response is dependent on gestational age.
authors.affiliation: Department of Obstetrics and Gynecology, Rikshospitalet University Hospital, University of Oslo, Oslo, Norway. guttorm.haugen@rikshospitalet.no
authors.forename: Guttorm
authors.initials: G
authors.lastname: Haugen
mesh_terms: D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D066298:In Vitro Techniques; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011247:Pregnancy; D012701:Serotonin / Q000494:pharmacology*; D018490:Serotonin Agents / Q000494:pharmacology; D014469:Umbilical Arteries / Q000187:drug effects* / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D018490:Serotonin Agents; D012701:Serotonin