ANTAGONISM OF THE HUMAN THROMBOXANE A2 RECEPTOR BY AN ANTIASTHMATIC AGENT-AA-2414

The human thromboxane A2 receptor (TXA2-R)-coding gene was introduced into Chinese hamster ovary cells and a cell line (TCHO-25) stably expr essing TXA2-R, at a level of 3 x 10(5)/cell, was obtained. An anti-ast hmatic agent AA-2414 -trimethyl-1,4-benzoquinon-2-yl)-7-phenylheptanoi c acid] competitively inhibited the specific binding of a TXA2 mimic ( [H-3]U-46619) to the TCHO-25 cells, with an IC50 of 6.0 x 10(-8) M, in dicating that the drug is an antagonist of human TXA2-R. The TCHO-25 c ells offer a tool for the screening and characterization of human TXA2 -R antagonists.