FIG. 6.

SLC26A3 and CFTR are involved in the HCO₃⁻-induced hyperpolarization. Measurements of membrane potential using DISC₃(5) in noncapacitated mouse spermatozoa. On the left are Representative fluorescent traces with internal calibration using valinomycin (val) and subsequent KCl additions to determine the Em obtained by HCO₃⁻ addition. The Em values (calculated with the internal calibration, right side of the trace) before and after the addition of HCO₃⁻ are indicated in each trace (arrows) in the presence of DMSO (A), Tdap (B), DOG (C), or inh-172 (D). On the right is a summary of the initial Em (In), the Em reached after the HCO₃⁻ addition (HCO₃⁻) in the absence (black bars) or presence of SLC26A3 (Tdap and 5099), SLC26A6 (DOG and PMA) or CFTR (inh-172) inhibitors (gray bars) at the indicated concentrations. Results are means ± SEM. N.S., P > 0.05; *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001 (n = 3).