Nucleotide-mediated relaxation in guinea-pig aorta: selective inhibition by MRS2179.

ABSTRACT: The vasodilatory effects of nucleotides in the guinea-pig thoracic aorta were examined to determine the relationship between molecular expression and function of P2Y receptors. In aortic rings precontracted with norepinephrine, vasodilatory responses to purine nucleotides exhibited a rank-order of potency of 2-methylthio-ATP>ADP>ATP. Responses to UTP, but not UDP suggested a functional role for P2Y4 but not P2Y6 receptors. Aortic endothelial cells express at least four P2Y receptors; P2Y1, P2Y2, P2Y4 and P2Y6. In primary culture, these cells exhibit desensitizing transient calcium responses characteristic of P2Y1, P2Y2 and P2Y4, but not P2Y6 receptors. UDP had no effect on endothelial cell calcium. The pyrimidinergic receptor agonist UTP is capable of eliciting robust vasodilation in aorti

SUBMITTER: Kaiser RA 

PROVIDER: S-EPMC1573141 | biostudies-literature | 2002 Jan

REPOSITORIES: biostudies-literature