A metabolite of Propranolol.
The main metabolite of (S)-Propranolol
The main metabolite of (R)-Propranolol
(±)-4-hydroxy propranolol, an active metabolite of propranolol, blocks β1- and β2-adrenergic receptors (β1-ars, β2-ars). also, (±)-4-hydroxy propranolol has antioxidant properties at micromolar concentrations. β1- and β2-ars, expressed in cardiac myocytes, mediate an increase in contractility by gs-dependent coupling to adenylyl cyclase.
compared to the control, (±)-4-hydroxy propranolol potently blocked the lipid peroxidation in a concentration-dependent fashion in endothelial cells. when pretreated with (±)-4-hydroxy propranolol at 0.067 to 6.7 μm, the degrees of protection were increased against the glutathione loss in the endothelial cells. additionally, (±)-4-hydroxy propranolol effectively preserved the loss of cell survival because of the radical stress [1].
rats were injected intravenously with (±)-4-hydroxy propranolol into the femoral vein at 0.1 ml/100 g. (±)-4-hydroxy propranolol induced an increase in heart rate in a dose-dependent manner in rats depleted of catecholamines, which suggested that (±)-4-hydroxy propranolol had intrinsic sympathomimetic activity. the response of (±)-4-hydroxy propranolol was inhibited when rats were pretreated with 0.5 mg/kg propranolol [2].
1.1 μm: inhibits lipid peroxidation in endothelial cells.
[1]. mak, i. potent antioxidant properties of 4-hydroxyl-propranolol. journal of pharmacology and experimental therapeutics. 2003; 308(1): 85-90.
[2]. fitzgerald, j., & o'donnell, s. pharmacology of 4-hydroxypropranolol, a metabolite of propranolol. british journal of pharmacology. 1971; 43(1): 222-235.
