TABLE 2.

Negative logarithm of antagonist equilibrium dissociation constants (pK_B) as estimated from Gaddum analysis of functional inhibition of 1 to 100 nM NECA in the absence and presence of Brilliant Black BN at the adenosine A₁ and A₃ receptors

Data represent the mean ± S.E.M. of three to nine experiments conducted in duplicate.

	Brilliant Black BN
	0 μM	500 μM
A1-CHO
DPCPX	8.6 ± 0.1	8.4 ± 0.1
XAC-X-BY630	6.9 ± 0.1	5.3 ± 0.2*
XACa	7.1 ± 0.1	5.6 ± 0.1*
A3-CHO
MRS1220	9.7 ± 0.1	9.1 ± 0.1*
XAC-X-BY630	7.7 ± 0.2	5.9 ± 0.1*
XACb	7.5 ± 0.1	6.0 ± 0.1*

^a pK_B values represent the average calculated from the inhibition of 1 nM and 10 nM NECA. There was no significant difference (P > 0.05; unpaired t test) between corresponding pK_B values determined in the presence of 1 nM and 10 nM NECA.

^b pK_B values represent the average calculated from the inhibition of 10 nM and 100 nM NECA. There was no significant difference (P > 0.05; unpaired t test) between corresponding pK_B values determined in the presence of 10 nM and 100 nM NECA.

^* Significantly different (P < 0.05; unpaired t test) from the corresponding value in the absence of Brilliant Black BN.