Binding of an [125I] labelled thromboxane A2/prostaglandin H2 receptor agonist to baboon platelets.
To characterize the thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor on baboon platelets the binding of [125I]BOP was studied. [125I]BOP bound to washed baboon platelets in a saturable manner. Scatchard analysis of binding isotherms revealed a Kd of 1.12 +/- 0.08 nM and a binding capacity of 54 +/- 5 fmoles/10(8) platelets (326 sites/platelet). Several TXA2/PGH2 agonists and antagonists displaced [125I]BOP from its baboon platelet binding site with a rank order of potency similar to human platelets: I-BOP greater than SQ29548 greater than U46619 = I-PTA-OH greater than PTA-OH. I-BOP aggregated washed baboon platelets with an EC50 of 10 +/- 4 nM. The results indicate that [125I]BOP binds to the TXA2/PGH2 receptor on baboon platelets and that this receptor is similar to its human counterpart.
Dorn
G W
GW
Department of Medicine, University of Texas Health Science Center, San Antonio.
De Jesus
A
A
D000818:Animals; D001667:Binding, Competitive; D001792:Blood Platelets / Q000648:ultrastructure*; D007457:Iodine Radioisotopes; D008297:Male; D010215:Papio; D010974:Platelet Aggregation / Q000187:drug effects; D011982:Receptors, Prostaglandin / Q000378:metabolism / Q000502:physiology*; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2
D007457:Iodine Radioisotopes; D011982:Receptors, Prostaglandin; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2