Prostaglandin receptors coupled to adenylyl cyclase in the iris-ciliary body of rabbits, cats and cows.
Stimulation of adenylyl cyclase by prostaglandin (PG) receptor agonists was examined in the iris-ciliary body of rabbits, cats and cows. Iris-ciliary bodies were incubated with or without agonists in Krebs pyruvate buffer containing protease and cyclooxygenase inhibitors. The formation of cAMP in a 15-min period in response to the agonists was measured. In the rabbit iris-ciliary body, all PG receptor agonists at concentrations of 0.062-10.0 microM with the exception of sulprostone stimulated adenylyl cyclase. In this species, 17-phenyl trinor PGE2 and PGF2 alpha stimulated adenylyl cyclase but only at high concentrations (> 5 microM). The order of potency of the agonists was dimethyl PGE2 > PGE2 > 11-deoxy PGE1 = PGD2 > iloprost > PGF2 alpha. The DP receptor antagonist BWA868C had no effect on EP agonist responses, indicating that PGE2, dimethyl PGE2 and 11-deoxy PGE1 were not stimulating DP receptors. In the cat, PGE2, dimethyl PGE2 and 11-deoxy PGE1, were all equally potent in stimulating adenylyl cyclase. The order of potency in the cow was PGE2 > dimethyl PGE2 > 11-deoxy PGE1. However, PGD2, iloprost, 17-phenyl trinor PGE2 and PGF2 alpha were inactive in this species. The results of this study indicate that EP receptor agonists stimulate adenylyl cyclase in the iris-ciliary body of the three species; stimulation by other agonists depends on the species. In the rabbit, the EP2 receptor subtype appears to predominate; such a predominance of EP2 receptors was not observed in the cat and cow.
Kentucky Lions Eye Research Institute, University of Louisville School of Medicine 40292.
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Bhattacherjee
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Rhodes
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Paterson
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002415:Cats; D002417:Cattle; D002924:Ciliary Body / Q000201:enzymology*; D000242:Cyclic AMP / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D007498:Iris / Q000201:enzymology*; D011453:Prostaglandins / Q000494:pharmacology; D011817:Rabbits; D011982:Receptors, Prostaglandin / Q000378:metabolism*; D013997:Time Factors
D011453:Prostaglandins; D011982:Receptors, Prostaglandin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases