Table 1

Inhibition of receptor agonist binding: affinity estimates for suramin and NF037

Human A1 receptorRat A1 receptorHuman D2 receptor
ControlReconstitutedControlReconstitutedControlReconstituted
Suramin IC50m)5.2  ± 1.05.4  ± 1.20.57  ± 0.11.66  ± 0.50.21  ± 0.010.23  ± 0.07
NF037 IC50m)92  ± 18112  ± 208.5  ± 3.223.9  ± 110.16  ± 0.010.18  ± 0.06

IC50 mean ± standard deviation values were calculated by fitting the data shown in Figs. 1 and 4 to a four-parameter logistic equation [B = Bo*(InH/(InH· + IC50nH)+ C, where B is the radioligand bound, Bo is the radioligand bound in the absence of inhibitor, I is the concentration of the inhibitor, nH is the slope of the curve, and C is the term estimating residual binding insensitive to the effect of suramin analogues].