Constriction to ETB receptor agonists, BQ-3020 and sarafotoxin s6c, in human resistance and capacitance vessels in vivo.
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.
Strachan
F E
FE
Clinical Pharmacology Unit & Research Centre, Department of Medical Sciences, University of Edinburgh, Western General Hospital, Edinburgh.f.strachan@ed.ac
Crockett
T R
TR
Mills
N L
NL
Gray
G A
GA
Webb
D J
DJ
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*
D016232:Endothelins; D010446:Peptide Fragments; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6; C075771:BQ 3020