The efficacy of practolol-induced beta1 adrenergic blockade in the canine heart

The efficacy of adrenergic blockade with practolol was assessed by subjecting 6 adult mongrel dogs in a closed-chest procedure to bolus injections of isoproterenol (0.5 mcg/kg, i.v.) before and after practolol (2.0 mg/kg, i.v.). Following practolol both heart rate and pulse pressure responses were significantly reduced. It is suggested that significant beta1 receptor adrenergic blockade is achieved by practolol.