Fig. 3. The inhibition of short-circuit current (I_sc) by the addition of Ba²⁺ to the mucosal Ringer's solution. The x axis scale reflects the sequence of treatments, which were applied at approximately regular intervals. In these experiments, the mucosal and serosal baths were NaCl Ringer. I_sc values marked with an asterisk are significantly inhibited relative to the control value. Removal of Ba²⁺ restores I_sc to its control value. The changes in the power density of the Lorentzian plateau at low frequencies (S_o) and the corner frequency (f_c) are not significant. Values are means ± S.E.M., N=6.