TABLE 1
Potencies of suramin analogs at recombinant P2X receptors The Cheng-Prusoff equation (eq. 3) was used to calculate Ki values from the IC50 values determined in this study for NF110, NF448, MK3 (Figs. 2, 4, and 5) and the published IC50 values for NF449 (Rettinger et al., 2005). Also used in the calculation were the following EC50 values obtained for the various P2X receptor subtypes in this laboratory: 0.68 μM ATP (rP2X1), 19.9 μM ATP (rP2X2), 0.67 μM ATP (rP2X3), 17.6 μM ATP (rP2X2-X3), and 1.7 μM α,β-meATP (rP2X2+3). A competitive antagonism is supported by a Schild plot analysis (Fig. 4E). n indicates the number of independent experiments.