Characterization of the coronary vascular -adrenoceptor in the pig

The beta-adrenoceptor in pig coronary vascular smooth muscle has been characterized by the use of a selective agonist, salbutamol and a selective antagonist, practolol. In coronary artery strips contracted with KCI, salbutamol had only marginal relaxant activity and was a partial agonist compared with isoprenaline. Practolol had relatively high antagonist potency against isoprenaline (pA(2) 6.59). It is concluded that the pig coronary vascular,beta-adrenoceptor is of the beta(1)-type.