title: Divergent effects of serotonin on coronary-artery dimensions and blood flow in patients with coronary atherosclerosis and control patients.
abstract: BACKGROUND
  Studies in animals have shown that serotonin constricts coronary arteries if the endothelium is damaged, but in vitro studies have revealed a vasodilating effect on isolated coronary segments with an intact endothelium. To investigate the effect of serotonin in humans, we studied coronary-artery cross-sectional area and blood flow before and after the infusion of serotonin in seven patients with angiographically normal coronary arteries and in seven with coronary artery disease.
  
  
  METHODS
  We measured the cross-sectional area of the coronary artery by quantitative angiography and coronary blood flow with an intracoronary Doppler catheter. Measurements were obtained at base line and during intracoronary infusions of serotonin (0.1, 1, and 10 micrograms per kilogram of body weight per minute, for two minutes). We repeated the measurements after an infusion of ketanserin, an antagonist of serotonin receptors that is thought to block the effect of serotonin on receptors in the arterial wall but not in the endothelium.
  
  
  RESULTS
  In patients with normal coronary arteries, the highest dose of serotonin increased cross-sectional area by 52 percent (P less than 0.001) and blood flow by 58 percent (P less than 0.01). The effect was significantly potentiated by administration of ketanserin. In patients with coronary-artery atherosclerosis, serotonin reduced cross-sectional area by 64 percent (P less than 0.001) and blood flow by 59 percent (P less than 0.001). Ketanserin prevented this effect.
  
  
  CONCLUSIONS
  Serotonin has a vasodilating effect on normal human coronary arteries; when the endothelium is damaged, as in coronary artery disease, serotonin has a direct, unopposed vasoconstricting effect. When considered with other evidence, these data suggest that platelet-derived factors such as serotonin may have a role in certain acute coronary ischemic syndromes.
authors.affiliation: Department of Internal Medicine, Second School of Medicine, University of Naples, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Golino
authors.forename: F
authors.initials: F
authors.lastname: Piscione
authors.forename: J T
authors.initials: JT
authors.lastname: Willerson
authors.forename: M
authors.initials: M
authors.lastname: Cappelli-Bigazzi
authors.forename: A
authors.initials: A
authors.lastname: Focaccio
authors.forename: B
authors.initials: B
authors.lastname: Villari
authors.forename: C
authors.initials: C
authors.lastname: Indolfi
authors.forename: E
authors.initials: E
authors.lastname: Russolillo
authors.forename: M
authors.initials: M
authors.lastname: Condorelli
authors.forename: M
authors.initials: M
authors.lastname: Chiariello
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000033:anatomy & histology / Q000473:pathology*; D004730:Endothelium, Vascular / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007650:Ketanserin / Q000494:pharmacology; D008875:Middle Aged; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D012701:Serotonin; D007650:Ketanserin