PD-156707 is an orally active, nonpeptide and selective Endothelin-A receptor antagonist.
PD-156707 binds to human ETA receptors with an approximately 800-fold higher affinity than to human ETB receptors[1].PD-156707 inhibits functional responses to ET-1, including inositol phosphate production in Ltk cells expressing recombinant human ETA receptors (IC50 = 2.4 nM) and arachidonic acid release in rabbit renal artery VSMC cells (IC50 = 1.1 nM)[1].
References:
[1]. Andrew C. G. Uprichard, et al. PD- 156707: A Selective Endothelin-A Receptor Antagonist. Cardiovascular Drug Reviews Vol. 16, No. 2, pp. 89-104. [2]. D P Ignasiak, et al. Effects of endothelin ETA receptor antagonism with PD 156707 on hemodynamics and renal vascular resistance in rabbits. Eur J Pharmacol. 1997 Mar 5;321(3):295-300.