SR 142801, The first potent non-peptide antagonist of the tachykinin NK3 receptor

Abstract SR 142801 is the first potent and selective non-peptide antagonist of the tachykinin NK 3 receptor. It inhibited [MePhe 7 ]NKB binding to its receptor from various species, including humans. SR 142801 was a competitive antagonist of [MePhe 7 ]NKB-mediated contractions of guinea-pig ileum and inhibited the acetylcholine release following the activation of the guinea-pig ileum tachykinin NK 3 receptor. In vivo, SR 142801 potently inhibited the turning behaviour induced by intrastriatal injection of senktide in gerbils, and appears as a powerful tool for investigation of the physiological and pathological role of NKB and its NK 3 receptor.