Table 4.

Inverse agonist effects of fluorescent XAC derivatives

Antagonist	(log EC50)	n	Fold increase
XAC	−7.15 ± 0.14	9	1.41 ± 0.07
XAC-X-BY630	−6.93 ± 0.12	9	1.32 ± 0.04
XAC-X-Texas Red	−5.82 ± 0.22	6	1.26 ± 0.06
XAC-dansyl	−6.84 ± 0.16	9	1.47 ± 0.08
XAC-AO-dansyl	−7.52 ± 0.17	7	1.20 ± 0.03
XAC-AHH-dansyl	−6.80 ± 0.14	5	1.40 ± 0.10

Values represent mean ± SEM of n separate experiments.

AHH, 6-(6-aminohexanamido)hexanoyl (see Figures 1 and 2 for complete structures); AO, 8-aminooctanoyl; X, 6-aminohexanoyl; XAC, xanthine amine congener.