ICI 118,551 hydrochloride

ICI 118,551 is a highly selective β2 adrenergic receptor antagonist (Kis: 0.7, 49.5, and 611 nM for β2, β1, and β3 receptors) . (In Vitro) :Zenidolol (ICI-118551) hydrochloride inhibits cAMP accumulation with IC50 of 1.7 μM in IMCD cells.Zenidolol (ICI-118551; 10 μM) hydrochloride induces a prominent vasorelaxation of norepinephrine (NE) -precontracted PA but not AO.In failing human heart, Zenidolol (ICI-118551) hydrochloride has significant effects on beat duration, with time-to-peak contraction and time-to-90% relaxation reduced compared with basal contraction. Negative Inotropic Effect of Zenidolol (ICI-118551) hydrochloride Is Not cAMP-Related. Overexpression of β2AR in rabbit myocytes enhances negative inotropic effects of Zenidolol (ICI-118551) hydrochloride. (In Vivo) :Zenidolol (ICI-118551; 0.2 mg/kg) hydrochloride injected into the jugular vein of the mice, reduces systolic pressure in the pulmonary circuit but not systemic arterial pressure.