SKF 86466 is an antagonist of α-adrenergic receptors (α-ARs; Ks = 9.4, 16, and 20 nM for α, α, and α receptors, respectively). It is selective for α-ARs over α-ARs (Ks = 449, 485, and 126 nM for α, α, and α receptors, respectively). SKF 86466 inhibits contractions in rabbit aorta and canine saphenous vein induced by norepinephrine or B-HT 920 , respectively (Ks = 600 and 42 nM, respectively). It decreases diastolic blood pressure in DOCA-salt hypertensive, spontaneously hypertensive, and two kidney-one clip (2K-1C) renal hypertensive rats when administered at a dose of 2 mg/kg, i.v. SKF 86466 (1 mg/kg) reduces muscle rigidity induced by reserpine in a mouse model of Parkinson’s disease.