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Characterization of the prostanoid receptors mediating constriction and relaxation of human isolated uterine artery
Author(s) -
Baxter G.S.,
Clayton J.K.,
Coleman R.A.,
Marshall K.,
Sangha R.,
Senior J.
Publication year - 1995
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1995.tb16393.x
Subject(s) - prostaglandin e2 receptor , prostanoid , agonist , receptor , endocrinology , medicine , uterine artery , prostaglandin , chemistry , phenylephrine , constriction , pharmacology , biology , pregnancy , gestation , genetics , blood pressure
1 This study was undertaken to characterize pharmacologically the prostanoid receptor subtypes mediating constriction and relaxation of human isolated uterine artery. 2 U‐46619 was a potent constrictor agonist on human uterine artery (EC 50 [95% CL] = 3.5 [1.8‐6.7] μ M ). Prostaglandin E2 (PGE 2α ), PGF 2 , PGD 2 and PGI 2 only weakly constricted the uterine artery, being at least 100 times less potent than U‐46619. The PGE 2 and PGI 2 constrictor effects may be modified by the potent dilator effects of these compounds. A number of agonists which show selectivity for FP‐, DP‐ and EP‐receptors including ICI 81008, BW 245C, sulprostone, rioprostil and butaprost, failed to cause any constriction at concentrations up to 30 μ M . 3 Constrictor responses induced by all agonists tested were reduced or abolished by the TP‐receptor blocking drugs, GR 32191 and EP 092. pA 2 estimates for both antagonists versus U‐46619 were 8.50, values which are consistent with their affinities at TP‐receptors. 4 In preparations pre‐constricted with phenylephrine (1 μ M ) both PGI 2 and PGE 2 were potent relaxant agonists. The selective IP‐receptor agonists, cicaprost and iloprost, also dilated human uterine artery and were approximately 10 fold more potent than PGI 2 . The EP 2 ‐receptor agonists, butaprost and rioprostil and the selective DP‐agonist, BW 245C, were at least 100 fold weaker than PGI 2 and PGE 2 suggesting that neither DP‐ nor EP 2 receptors were involved. 5 We conclude that TP‐receptors mediate constriction, whereas IP‐ and possibly EP 4 ‐receptors mediate relaxation of human uterine artery.