title: Effects of serotonin on vascular tone of isolated human placental chorionic veins.
abstract: Vasomotor effects of serotonin (5-hydroxytryptamine; 5-HT) were studied in isolated human placental chorionic veins in vitro. 5-HT produced marked contraction with a maximum of 89 +/- 5.05% of the K(+)-induced contractions. This response was specifically and competitively antagonized by ketanserin at doses of 10(-9) and 10(-8) M (pA2 = 9.65). Ketanserin, at concentrations up to 10(-7) M, induced noncompetitive inhibition of the contractions. These findings show a marked vasoconstrictor effect of 5-HT on the capacitance vessels of the human placenta, which suggests that this amine could play an important role as a mediator of fetal circulation. The possible therapeutic effect of ketanserin as a vasodilator to improve blood flow in the uteroplacental unit, is also discussed, based on the ability of this drug to block competitively 5-HT effects on chorionic veins.
authors.affiliation: Departamento de Ciencias Fisiológicas, Facultad de Ciencias Biológicas y de Recursos Naturales, Universidad de Concepción, Chile.
authors.forename: C
authors.initials: C
authors.lastname: Gonzalez
authors.forename: M A
authors.initials: MA
authors.lastname: Cruz
authors.forename: W H
authors.initials: WH
authors.lastname: Sepulveda
authors.forename: M I
authors.initials: MI
authors.lastname: Rudolph
mesh_terms: D002823:Chorion / Q000098:blood supply*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D007650:Ketanserin / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D012701:Serotonin; D007650:Ketanserin