TABLE 3.

Affinity values obtained for ligands in human bronchial smooth muscle cells (that natively express β₂-AR) and in CHO-β₂ cells that stably express a transfected human β₂-AR determined from antagonism of cimaterol-induced ³H-cAMP accumulation

Antagonist	Human bronchial smooth muscle cells		CHO-β2 cells
	Log Kd	n	Log Kd	n
CGP20712A	−6.06 ± 0.08	4	−6.02 ± 0.03	8
ICI118551	−9.51 ± 0.13	4	−9.65 ± 0.03	6
NDD-713	−5.47 ± 0.05	4	−5.44 ± 0.03	4
NDD-825	−5.87 ± 0.11	4	−5.75 ± 0.06	4

Log K_d values shown are means ± sem of n separate experiments.