Isoproterenol is a selective β-adrenoceptor agonist that shows high affinity for β1, β2, and β3 (Ki = 224, 458, and 1,570 nM, respectively). Low concentrations of isoproterenol are sufficient to inhibit contractions in isolated field stimulated rat vas deferens (EC50 = 45.6 nM). Through its effects on β-adrenoceptor, isoproterenol increases cAMP levels and can activate protein kinase A and ERK1/2.
