Table 1.

Binding affinity of agonists and antagonists of adenosine receptors [K_i values with 95% confidence intervals (in parentheses) or ± SEM] (adapted from Fredholm et al., 2001)

Drug	A₁R	A_2AR	A_2BR	A₃R
CPA	2.3 (1.5–3.4)^{^a}	790 (470–1360)^{^a}	34,400 ± 11,100^{^b}	43 (30–61)^{^a}
			21,000 ± 4300^{^d}
CGS 21680	290 (230–360)^{^a}	27 (12–59)^{^a}	361,000 ± 21,100^{^b}	67 (50–90)^{^a}
DPCPX	3.9 (3.5–4.2)^{^a}	129 (35–260)^{^a}	50 ± 3.7^{^b}	4000 (2600–6000)^{^a}
DPCPX	3.9 (3.5–4.2)^{^a}	129 (35–260)^{^a}	51 ± 6.1^{^d}	4000 (2600–6000)^{^a}
SCH 58261	290 (210–410)^{^c}	0.6 (0.5–0.7)^{^c}		>10,000^{^c}

↵^aKlotz et al., 1998.
↵^bLinden et al., 1999.
↵^cOngini et al., 1999.
↵^dJi and Jacobson, 1999.