Table 1.

Properties of α,β-methylene-ATP concentration–effect curves with and without IVM on P2X₄ receptors alone or when expressed in combination with P2X₆ receptors

Receptor	α,β-Methylene-ATP	Threshold (μm)	EC₅₀ (μm)	Hill slope	I_max(−nA)^1-a	n
P2X₄	Control	300	>300	^1-b	433 ± 113	7
	+IVM (3 μm)	10	19.8 ± 3.7	2.0 ± 0.2	1608 ± 311	6
P2X₄/P2X₆	Control	10	25.1 ± 2.7*	1.8 ± 0.3	360 ± 50	8
	+IVM (3 μm)	3	15.6 ± 1.4*	2.2 ± 0.1	3739 ± 244	9

↵F1-a I_max is the largest current on the concentration–effect curve to α,β-methylene-ATP (100 or 300 μm).
↵F1-b The Hill slope was not possible to determine.
*Statistical difference (at p < 0.05) between these two EC₅₀ values (p = 0.005; unpaired Student’s t test; also see Figure 4 for graphs).