TABLE 2

Functional activity and selectivity of 5-HOB and formoterol against the different human β-AR subtypes

β1-AR and β2-AR were expressed in CHO cells; β3-AR was expressed in HEK293 cells. Emax values were determined relative to isoprenaline, a reference nonselective β-AR agonist. The values are expressed as mean ± S.E.M. of two to four independent experiments.

cAMP Response5-HOBFormoterol
EC50EmaxEC50Emax
nM%nM%
β1-AR793 ± 9240 ± 1.767 ± 3.884 ± 1.6
β2-AR3.5 ± 0.393 ± 0.70.3 ± 0.0397 ± 1.0
β3-AR925 ± 1197 ± 0.797 ± 1.4113 ± 7
β2-AR occupancy at % control [EC40]70.41.8