title: Constriction to ETB receptor agonists, BQ-3020 and sarafotoxin s6c, in human resistance and capacitance vessels in vivo.
abstract: OBJECTIVE
  The aim of the study was to examine the effects of the ETB receptor selective agonists sarafotoxin S6c (SFTX6c) and BQ-3020 on the forearm resistance and capacitance vessels in healthy subjects in vivo.
  
  
  METHODS
  The local response to intra-arterial or intravenous infusion of SFTX6c (5 pmol min-1) or BQ-3020 (50 pmol min-1) was assessed, on separate occasions, in eight healthy men (aged 20-28 years). Data (mean +/- s.e.mean) were examined by ANOVA. Results are expressed as percentage change from baseline at 90 min.
  
  
  RESULTS
  SFTX6c and BQ-3020 reduced forearm blood flow, following local intra-arterial infusion (-25 +/- 7% and -27 +/- 7%, respectively; P < 0.001) and reduced hand vein diameter, following local intravenous infusion (-30 +/- 8% and -16 +/- 7%, respectively; P < 0.001).
  
  
  CONCLUSIONS
  We have shown that locally active infusions of the selective ETB receptor agonists SFTX6c and BQ-3020 cause arterial constriction and venoconstriction in healthy human blood vessels in vivo. These results indicate that ETB receptor stimulation may mediate vasoconstriction in humans.
authors.affiliation: Clinical Pharmacology Unit & Research Centre, Department of Medical Sciences, University of Edinburgh, Western General Hospital, Edinburgh.f.strachan@ed.ac
authors.forename: F E
authors.initials: FE
authors.lastname: Strachan
authors.forename: T R
authors.initials: TR
authors.lastname: Crockett
authors.forename: N L
authors.initials: NL
authors.lastname: Mills
authors.forename: G A
authors.initials: GA
authors.lastname: Gray
authors.forename: D J
authors.initials: DJ
authors.lastname: Webb
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D016232:Endothelins / Q000008:administration & dosage*; D005542:Forearm / Q000098:blood supply*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage*; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin / Q000819:agonists*; D018924:Vascular Capacitance / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*; D014757:Viper Venoms / Q000008:administration & dosage*
chemical_list: D016232:Endothelins; D010446:Peptide Fragments; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6; C075771:BQ 3020