This study demonstrates the high selectivity of DuP 753 for angiotensin II (AII) receptors as it did not inhibit the contractions or radioligand bindings od endothelin, neurotensin, substance P, opioids, dopamine-2, serotonin-2, phencyclidine, acetylcholine agonists and glycine (strychnine-insensitive) and basic fibroblast growth factor but blocked the contraction of AII.