Characterization of thromboxane A2/prostaglandin H2 receptors in human vascular smooth muscle cells.
The present study utilizes a newly synthesized TXA2/PGH2 mimetic, I-BOP, to characterize the TXA2/PGH2 receptor in suspensions of cultured human vascular smooth muscle cells. [125I]-BOP bound in a saturable and specific manner (Kd = 2.6 +/- 0.6 nM; Bmax = 33,540 +/- 6,200 sites/cell; 69 fmoles/mg protein, n = 12). Competition binding assays were performed with [125I]-BOP and the TXA2/PGH2 receptor antagonists SQ29548, L657925 and L657926 and the receptor agonist U46619. I-BOP induced concentration-dependent increases in intracellular free calcium which were inhibited by SQ29548. The results provide radioligand binding evidence for the presence of a TXA2/PGH2 receptor in human vascular smooth muscle cells.
Morinelli
T A
TA
Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston 29425.
Mais
D E
DE
Oatis
J E
JE
Crumbley
A J
AJ
Halushka
P V
PV
D001667:Binding, Competitive; D002118:Calcium / Q000032:analysis; D002478:Cells, Cultured; D006801:Humans; D007700:Kinetics; D008024:Ligands; D009131:Muscle, Smooth, Vascular / Q000032:analysis* / Q000378:metabolism; D011449:Prostaglandin Endoperoxides / Q000378:metabolism*; D011463:Prostaglandins H / Q000378:metabolism*; D011982:Receptors, Prostaglandin / Q000032:analysis*; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2; D013928:Thromboxane A2 / Q000378:metabolism*
D008024:Ligands; D011449:Prostaglandin Endoperoxides; D011463:Prostaglandins H; D011982:Receptors, Prostaglandin; D017482:Receptors, Thromboxane; D044244:Receptors, Thromboxane A2, Prostaglandin H2; D013928:Thromboxane A2; D002118:Calcium