FIGURE 6.
Effects of DDT on AaNav1-1 and BgNav1-1a and mutant channels. A–D, representative sodium current traces elicited by a 20-ms depolarization from −120 to −10 mV from AaNav1-1, L2i16F, and L1o6I sodium channels after DDT treatment (10 or 100 μm). E, topology of a sodium channel indicating the position of all mutations that were tested in this study. Residues in PyR1 and PyR2 are indicated with open and solid circles, respectively. Corresponding positions of naturally occurring kdr mutations in the AaNav1-1or BgNav1-1a channel are indicated in parentheses. F and G, percentages of channel inactivation inhibited by DDT (100 μm). Eleven pairs of mutations were tested in both AaNav1-1or BgNav1-1a channels. The number of oocytes for each mutant construct was >8. Error bars indicate mean ± S.E. The asterisks indicate significant differences (p < 0.05) in sensitivity of mutants versus wild type to DDT as determined using one-way analysis of variance with Scheffé's post hoc analysis.