TABLE 2

Functional β₂ selectivity of agonists against the different human β-adrenergic receptor subtypes

CHO cells selectively expressing the human adrenergic β₁-, β₂-, and β₃-receptors were stimulated with increasing concentrations of agonists (0.03–10,000 nM), and cAMP levels were quantified as described under Materials and Methods. Data are reported as mean ± S.E.M. of three independent experiments. EC₅₀ is the concentration required to do 50% of the maximal effect (versus the reference agonists epinephrine, formoterol hemifurate, and ZD7114 for the β₁, β₂, and β₃ assays, respectively).