In vitro characterization of Ro 46‐2005, a novel synthetic non‐peptide endothelin antagonist of ETA and ETB receptors

Abstract

Ro 46-2005 is a new synthetic non-peptide endothelin (ET) receptor antagonist. In binding experiments, Ro 46-2005 proved to be equipotent (IC₅₀ 200–500 nM) for inhibition of [¹²⁵I]ET-1 binding on the two known ET receptor subtypes (ET_A and ET^B). Scatchard analysis was consistent with a competitive binding mode. Ro 46-2005 also inhibited the functional consequences of ET-1 stimulation: the ET-1-induced release of arachidonic acid from rat mesangial cells was inhibited with an IC₅₀ of 1.8 μM.