β1-adrenergic receptor

Practolol (10 μM; 30 min) preferentially antagonizes the relaxant effects produced by R0363 in spontaneously contracted tracheal preparations from the guinea-pig.
Practolol (10 nM-100 μM) blocks the progesterone production induced by (-)epinephrine in a dose-dependent manner in granulosa cells.

Practolol (0.5 mg/kg; i.v.) decreases heart rate, left ventricular dP/dt max , myocardial blood flow and cardiac output in intact close-chest dogs.
Practolol (0.5 mg/kg; i.v.) decreases normal myocardial blood flow but flow in the ischaemic area remains unchanged after coronary artery ligation.