Fig. 4.

Isochronic inhibition curves for A/M2, BM2, truncated A/M2, and chimeric BM2 ion channels by amantadine. Seven to nine different concentrations of amantadine were applied to oocytes expressing the ion channels for 2 min at pH 5.5, and the current was measured before and 2 min after drug addition. Three oocytes were used for each drug concentration, and results were averaged (mean ± SE). A dose–response relationship was applied to the results using Origin 6 software, and the best-fit IC₅₀ values for these ion channels are listed in Table 1.