The assessment of β-adrenoceptor blocking potency and cardioselectivity in vitro and in vivo

Abstract
The β-adrenoceptor blocking potencies and cardioselectivities (versus tracheal smooth muscle) of propranolol, practolol and M & B 17803A have been assessed on in vitro and in vivo guinea-pig preparations. Propranolol was found to be potent but non-selective, practolol to be less potent but cardioselective. M & B 17803A resembled practolol in potency but had a more modest degree of cardioselectivity in vivo. These observations suggest that the procedures used form a simple scheme which permits a probably relevant assessment of β-adrenoceptor blocking potency and cardioselectivity.