title: The binding of 6-oxo-prostaglandin E1 to platelet prostanoid receptors.
abstract: 6-oxo-PGE1 has been shown to cause a dose dependent stimulation of platelet adenylate cyclase (Km 1.6 X 10(-7)M). Since this compound also displaced specifically bound 9-3H-PGI2 from intact washed platelets (Ki 1.6 X 10(-6)M), the coupling to platelet PGI2 receptors has been suggested to account for the observed platelet cyclase stimulation. However, the Ki/Km-ratio of 6-oxo-PGE1 appears to be high (10.3) as compared to PGI2, ZK 36 374, and PGE1 (1.9, 2.4 and 3.1, resp.). Thus, one might expect that 6-oxo-PGE1 interacts with a heterogeneous population of platelet receptors mediating the same biological response, eg cyclase activation. In this study, we present evidence supporting this concept and report that 6-oxo-PGE1 also displaces specifically bound 3H-PGD2 from its platelet receptor (Ki 1.6 X 10(-5)M).
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000527:Alprostadil / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000097:blood; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects; D015230:Prostaglandin D2; D011453:Prostaglandins / Q000378:metabolism / Q000494:pharmacology; D011457:Prostaglandins D / Q000378:metabolism; D011982:Receptors, Prostaglandin / Q000378:metabolism*
chemical_list: D011453:Prostaglandins; D011457:Prostaglandins D; D011982:Receptors, Prostaglandin; C022950:6-ketoprostaglandin E1; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000527:Alprostadil; D015230:Prostaglandin D2