TABLE 1.

Comparison of the Binding Affinities (K_i Values in nM) of Various A₃ Adenosine Receptor Ligands in Rat (r) and Human (h) Species. (The Compounds are Selective in Binding to the Human A₃ Adenosine Receptor, Unless Noted.)

Compound	Ratio (r/h)	Ki hA3	Ki rA3	Ref.
Antagonists (non-nucleoside)
MRS 1067	10	561	5,500	37
MRS 1097	39	108	4,160	38
MRS 1191	45	31.4	1,420	39,40
MRS 1220	>1000	0.65	>1000	39,40
MRS 1523	6.0	18.9	113	40
MRE 3008F20	>30,000	0.29	>10,000	41
XACa	760	38	29,000	41,42
OT-7999	>16,000	0.61	>10,000	8
Agonists (nucleoside)
IB-MECA	0.61	1.8	1.1	39,43
Cl-IB-MECA	0.72	1.8	1.3	13,39
DBXRM	0.28	816	229	13,39
Antagonist (nucleoside)
MRS1292	1.7	29.3	49	13

^aNonselective.