title: Vasoactive response of isolated pulpal arterioles to endothelin-1.
abstract: The vasoactive effect of endothelin-1 applied intraluminally or extraluminally was studied in vitro in isolated perfused porcine pulpal arterioles using a microperfusion system. Pulpal arterioles (outer diameter, 94.2 +/- 2.8 microm, n = 12) were cannulated and perfused at a constant flow rate in an environment-controlled bath on the stage of an inverted microscope. The vessel diameters were measured online. Both intraluminal and extraluminal application of endothelin-1 (10(-16) M to 10(-8) M) induced dose-dependent constrictions, reaching 82.3 +/- 1.7% (n = 12) and 70.5 +/- 1.3% (n = 12) at 10(-8) M, respectively. Nifedipine reversed endothelin-1-induced constriction dose-dependently at 10(-7) M and above. These data demonstrate that endothelin-1 induces calcium-dependent vasoconstriction in porcine pulpal arterioles, with extraluminal application more potent, which seems to reflect the possible modulation of vascular endothelium in the control of vascular tone.
authors.affiliation: School of Dentistry, University of Western Australia, Nedlands, Australia. chrisyu@cyllene.uwa.edu.au
authors.forename: Christine Y
authors.initials: CY
authors.lastname: Yu
authors.forename: Nick M
authors.initials: NM
authors.lastname: Boyd
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cringle
authors.forename: Er-Ning
authors.initials: EN
authors.lastname: Su
authors.forename: Dao-Yi
authors.initials: DY
authors.lastname: Yu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001160:Arterioles / Q000187:drug effects; D003782:Dental Pulp / Q000098:blood supply*; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009543:Nifedipine