Endothelin ET(B) receptor-mediated constriction in the rabbit basilar artery.
The present study tests whether endothelin ET(B) receptor activation can mediate endothelin-1 constriction in the rabbit basilar artery in situ. Endothelin-1 (30 nM) induced 27% constriction of vessels pretreated with 1 microM BQ610 (homopiperidenyl-CO-Leu-DTrp (CHO)-D-Trp-OH), an endothelin ET(A) receptor antagonist, and the resulting constriction was completely relaxed by BQ788 (N-cis-2,6-dimethylpiperidinocarbonyl L-gamma-MeLeu-D-Trp (COOCH3)-Nle), an endothelin ET(B) receptor antagonist. Similarly, 30 nM endothelin-1 induced 30% constriction of vessels pretreated with 1 microM BQ788, and the resulting constriction was completely relaxed by BQ610. In contrast, sarafotoxin S6c, an endothelin ET(B) receptor agonist, did not induce constriction. This study suggests that in the basilar artery (1) endothelin ET(B) receptor activation can result in constriction and (2) the ability to elicit constriction is in some way dependent upon the agonist that activates the endothelin ET(B) receptor.
Department of Neurosurgery, University of Cincinnati College of Medicine, Veterans Affairs Medical Center, OH 45267-0575, USA.
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Boccaletti
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D000818:Animals; D001488:Basilar Artery / Q000502:physiology*; D019332:Endothelin-1 / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D011817:Rabbits; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin / Q000819:agonists / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects
D019332:Endothelin-1; D009842:Oligopeptides; D010880:Piperidines; D044023:Receptor, Endothelin B; D017466:Receptors, Endothelin; C087220:BQ 610; C086539:BQ 788