EMD 66684 is a synthetic antagonist of the Angiotensin II type 1 receptor. It has an effective concentration of 1-100 nM. EMD 66684 completely attenuates Angiotensin II-induced increases in basal and nerve stimulated neuropeptide Y (NPY) overflow from mesenteric arterial beds in a model of spontaneously hypertensive rats. In the same model EMD 66684 also attenuated the effect of ANG II on perfusion pressure