Table 1.

Affinity of various competing ligands at the human and rat A₃ARs expressed in CHO cells using [⁷⁶Br]4 as radioligand.

Compounda	Human Ki (nM)	Rat Ki (nM)
MRS1220	2.74 ± 0.77	>10,000
MRS1523	125 ± 13	939 ± 98
4 MRS3581	0.63 ± 0.05	0.90 ± 0.07
NECA	20.1 ± 2.5	143 ± 18

MRS 1220: N-[9-chloro-2-(2-furanyl)[1,2,4]triazolo[1,5-c]quinazolin-5-yl]benzeneacetamide; MRS1523: 5-propyl-2-ethyl-4-propyl-3-(ethylsulfanylcarbonyl)-6-phenylpyridine-5-carboxylate;

NECA: adenosine-5′-N-ethyluronamide.