Figure 6. Time course of I_sc in a hyposmotic solution with DPC (A), gluconate (B) or NO₃⁻ (C).

A, DPC (2 mM; bilateral application) decreased the I_sc. In the presence of DPC, nystatin (50 μM, NYS; apical application) induced a small current. Ouabain (1 mM, OUA; basolateral application) diminished the nystatin-induced I_sc. B, in a gluconate solution, nystatin induced an increase in I_sc, which was larger than that in the presence of DPC (A) but much smaller than control (see Fig. 4A). Ouabain (1 mM, OUA; basolateral application) diminished the nystatin-induced I_sc. C, in a NO₃⁻ solution, nystatin induced a large increase in I_sc similar to control (see Fig. 4A). Ouabain (1 mM, OUA; basolateral application) diminished the nystatin-induced I_sc. n = 4-8.