TABLE 3

Displacement of specific [³H]ZM241385 binding by amiloride and HMA from wild-type human A_2AAR and point mutants D52A^2.50, S91A^3.39, W246A^6.48, N280A^7.45, N284A^7.49 transiently expressed on HEK293 cell membranes

Values are means ± S.E.M. of at least three separate assays performed in duplicate.

	[³H]ZM241385
	Amiloride		HMA
	IC₅₀	Change^a	IC₅₀	Change^a
	µM		µM
Wild type	63 ± 16	1.0	8.9 ± 1.5	1.0
D52A^2.50	1065 ± 274***	17	164 ± 47***	18
S91A^3.39	82 ± 8		8.2 ± 0.5	0.92
W246A^6.48	2.6 ± 0.4***	0.04	0.36 ± 0.06***	0.04
N280A^7.45	20 ± 4	0.32	2.5 ± 0.6**	0.28
N284A^7.49	16 ± 4*	0.25	3.3 ± 0.8*	0.37

↵^a Change in fold over wild-type.
Significantly different from wild type with *P < 0.05, **P < 0.01, or ***P < 0.001 (one-way analysis of variance with Dunnett’s posttest performed on corresponding pIC₅₀ values).