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[3-[4-(4,5-Diphenyl-2-oxazolyl)-5-oxazolyl]phenoxy]acetic Acid (BMY 45778) Is a Potent Non-Prostanoid Prostacyclin Partial Agonist: Effects on Platelet Aggregation, Adenylyl Cyclase, cAMP Levels, Protein Kinase, and Iloprost Binding

S M Seiler, C L Brassard, M E Federici, J Romine, N A Meanwell

Prostaglandins. 1997 Jan;53(1):21-35.

PMID: 9068064

Abstract:

[3-[4-(4,5-diphenyl-2-oxazolyl)-5-oxazolyl]phenoxy]acetic acid (BMY 45778) inhibits human (IC50 = 35 nM), rabbit (136 nM) and rat (1.3 microM) platelet aggregation. This compound activates adenylyl cyclase (ED50 = 6-10 nM) and stimulates GTPase in human platelet membrane preparations. The potency (EC50) of BMY 45778 stimulating adenylyl cyclase is comparable to iloprost. However, maximal stimulation of GTPase by BMY 45778 is approximately half the iloprost-stimulated activity, and BMY 45778 limits the GTPase stimulation by iloprost suggesting that BMY 45778 is a partial agonist at the IP receptor. BMY 45778 completely prevents [3H]]Iloprost binding to platelet membranes (IC50 = 7 nM). In whole platelets, BMY 45778 causes elevation of platelet cAMP levels (cAMP content doubles at 13 nM) and activation of the cAMP-dependent protein kinase (cAMP-protein kinase ratio is twice basal at 2 nM). BMY 45778 treatment of whole platelets also desensitizes the adenylyl cyclase activation by iloprost. These results indicate that BMY 45778, which is structurally different from prostacyclin and most prostacyclin agonists, acts by stimulating prostacyclin (IP) receptors.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP152575661 BMY 45778 BMY 45778 152575-66-1 Price
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