title: Binding of a thromboxane A2/prostaglandin H2 agonist [3H]U46619 to washed human platelets.
abstract: The binding characteristics of [3H]U46619 to washed human platelets were studied. [3H]U46619 binding to washed human platelets was saturable and displaceable. Kinetic studies yielded a Kd of 11 +/- 4 nM (n = 4). Scatchard analysis of equilibrium binding studies revealed one class of high affinity binding sites with a Kd of 20 +/- 7 nM and a Bmax of 9.1 +/- 2.3 fmole/10(7) platelets (550 +/- 141 binding sites per platelet) (n = 4). A number of compounds that act as either agonists or antagonists of the TXA2/PGH2 receptor were tested for their ability to inhibit the binding of [3H]U46619 to washed human platelets. The Kds of the agonists and antagonists were similar to their potencies to induce or inhibit platelet aggregation. These data provide some evidence that [3H]U46619 binds to the putative human platelet TXA2/PGH2 receptor.
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D001667:Binding, Competitive; D001792:Blood Platelets / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D010974:Platelet Aggregation / Q000187:drug effects; D011450:Prostaglandin Endoperoxides, Synthetic / Q000097:blood*; D011982:Receptors, Prostaglandin / Q000378:metabolism; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2
chemical_list: D011450:Prostaglandin Endoperoxides, Synthetic; D011982:Receptors, Prostaglandin; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid