Figure 3.

Concentration-dependent inhibition of ATP-activated P2X4 currents by t-DCA. (A) Representative P2X4-mediated whole-cell current traces recorded in individual matched oocytes from the same batch of oocytes in the absence of t-DCA or in the presence of t-DCA in the indicated concentrations. ATP (10 µM) and t-DCA were present in the bath solution as indicated by open and filled bars, respectively. Zero current level is indicated by a dotted horizontal line. (B) Concentration–response relationship of the inhibitory effect of t-DCA on ATP-activated P2X4 currents. Summary of normalized ATP-activated P2X4 current responses from similar experiments as shown in A. The current integral of each recording was normalized to the mean current integral obtained under control conditions (i.e., in the absence of t-DCA) for the corresponding batch of oocytes. Data are means ± SEM (25 ≤ n ≤ 26; N = 3) and were fitted to Eq. 1. IC₅₀, half maximal inhibitory concentration.