Abstract A series of pseudopeptides, analogues of neurokinin selective agonists, in which a peptide bond was replaced by a (CH 2 NH) bond were synthesized. The biological activities of these compounds were determined on selective pharmacological preparations: the dog carotid artery for NK-1, the rabbit pulmonary artery devoid of endothelium for the NK-2 and the rat portal vein for the NK-3 receptors. The results reported in this study indicate that ...