Table 1

Binding affinities (pK_i), potencies (pD₂) and intrinsic activities (IA) as stimulants of adenylyl cyclase in membranes from CHO cells expressing human cloned βARs^1-a

	β₁AR		β₂AR		β₃AR
	pK_i	pD₂		IA	pK_i	pD₂		IA	pK_i	pD₂		IA
	n		n		n		n		n		n
(−)-Isoproterenol	6.96 ± 0.13	6.45 ± 0.08		[1.0]	6.80 ± 0.19	6.79 ± 0.07		[1.0]	5.24 ± 0.11	5.87 ± 0.04		[1.0]
	4		29		3		20		5		47
(±)-CGP 12177	9.38 ± 0.14			0	8.97 ± 0.14			0	6.02 ± 0.06	5.73 ± 0.05		0.54 ± 0.03
	7		3		7		4		3		42
BRL-37344	4.97 ± 0.08			0.09 ± 0.04	6.33 ± 0.12	5.02 ± 0.19		0.34 ± 0.01	6.16 ± 0.04	5.97 ± 0.14		0.42 ± 0.03
	5		3		5		3		4		12
SB-215691	n.d.	4.81 ± 0.03		0.48 ± 0.04	n.d.	5.22 ± 0.11		0.74 ± 0.07	n.d.	6.11 ± 0.22		1.06 ± 0.07
			4				4				4
SB-220646	<4.3			0	<4.3			0	n.d.	6.00 ± 0.11		1.02 ± 0.25
	1		5		1		2				3
SB-226552	3.75 ± 0.10			0	3.96 ± 0.18			0	<4	5.63 ± 0.13		0.72 ± 0.03
	6		2		6		3		2		4
SB-229432	4.18 ± 0.15			0	5.34 ± 0.19			0	n.d.	6.12 ± 0.14		1.13 ± 0.10
	6		2		6		1				3
SB-232602	5.79 ± 0.20			0	5.94 ± 0.23			0	n.d.	6.29 ± 0.14		1.02 ± 0.07
	4		2		4		1				6
SB-236923	5.33 ± 0.14	6.47 ± 0.09		0.26 ± 0.03	6.01 ± 0.20	4.47		0.10	n.d.	6.92 ± 0.07		1.30 ± 0.07
	2		3		2		2				3
SB-246982	7.11 ± 0.08	6.86 ± 0.28		0.21 ± 0.03	6.32 ± 0.05			0	7.50 ± 0.06	9.13 ± 0.46		1.51 ± 0.17
	3		4		3		3
SB-248320	6.70 ± 0.04	6.67 ± 0.14		0.54 ± 0.01	6.56 ± 0.08			0	n.d.	7.98 ± 0.24		1.16 ± 0.07
	3		3		3		3				5

↵1-a Numbers of observations are given below each pK_i or pD₂ and intrinsic activity. n.d., Not determined.