Binding affinities of different β2-AR agonists against the three human β-adrenoceptor subtypes
The equilibrium dissociation constants (pKi) of the different ligands were determined in heterologous competition experiments against [3H]CGP 12177 in the presence of a GTP analog. The pKi values (± S.E.M.) shown are the average of at least three independent experiments performed in triplicate.
| Agonist | pKi hβ1 | pKi hβ2 | pKi hβ3 | Ratio β1/β2 | Ratio β3/β2 |
|---|---|---|---|---|---|
| Isoprenaline | 6.49 ± 0.01 | 6.54 ± 0.03 | 5.57 ± 0.07 | 1 | 9 |
| Olodaterol | 7.33 ± 0.05 | 9.14 ± 0.04 | 5.26 ± 0.14 | 65 | 7586 |
| Formoterol | 6.07 ± 0.04 | 8.29 ± 0.03 | 5.58 ± 0.12 | 166 | 513 |
| Salmeterol | 6.14 ± 0.02 | 9.24 ± 0.08 | 5.43 ± 0.01 | 1259 | 6457 |