Nomenclature	β1-adrenoceptor	β2-adrenoceptor	β3-adrenoceptor
HGNC, UniProt	ADRB1, P08588	ADRB2, P07550	ADRB3, P13945
Principal transduction	Gs	Gs	Gs
Rank order of potency	(-)-noradrenaline > (-)-adrenaline	(-)-adrenaline > (-)-noradrenaline	(-)-noradrenaline = (-)-adrenaline
Endogenous agonists (pKi)	noradrenaline (6.0) 356	–	–
Selective agonists (pKi)	(-)-Ro 363 (8.0) 380, xamoterol (Partial agonist) (7.0) 364, denopamine (Partial agonist) (5.8) 364,400	formoterol (pEC50 10.08) 334, salmeterol (pEC50 9.9) 334, zinterol (pEC50 9.48) 334, procaterol (pEC50 8.43) 334	carazolol (8.7) 376, BRL 37344 (6.4–7.0) 338,348,362,376, CGP 12177 (Partial agonist) (6.1–7.3) 338,373,376,380, CL316243 (5.2) 411, L 755507 (pEC50 10.1) 334, L742791 (pEC50 8.8) 408, SB251023 (pEC50 7.14 - Mouse) 363
Selective antagonists (pKi)	CGP 20712A (8.5–9.2) 332,341,373, betaxolol (8.8) 373, atenolol (6.7–7.6) 332,366,373	ICI 118551 (Inverse agonist) (9.2–9.5) 332,335,373	L-748337 (8.4) 341, SR59230A (6.9–8.4) 341,347,362
Radioligands (Kd)	[125I]ICYP (Antagonist, it is necessary to use an excess of a β2-AR-selective ligand such as ICI 118551 to allow visualisation of β1-AR binding in native tissue) (4.99x10-12–3.28x10-11 M) 373,395	[125I]ICYP (Antagonist, it is necessary to use an excess of a β1-AR-selective ligand such as CGP20712A to allow visualisation of β2-AR binding in native tissues) (7.9x10-12 M) 373,395	[125I]ICYP (Agonist, Partial agonist) (1.58x10-10–6.31x10-10 M) 373,380,385,395,399
Comment	The agonists indicated have less than two orders of magnitude selectivity 334.	–	Agonist SB251023 has a pEC50 of 6.9 for the splice variant of the mouse β3 receptor, β3b 363.