Figure 13. Time courses of I_sc and conductance in the presence and absence of a PTK inhibitor, tyrphostin A23 (TY23), after exposure of cells to a hyposmotic solution.

A, TY23 (100 μM, bilateral application) diminished the basal I_sc (▪). The I_sc increased by nystatin (NYS, 50 μM, apical application) was diminished by TY23 treatment. The ouabain-sensitive current was also much smaller in the presence (▪) than in the absence of TY23 (□). B, TY23 decreased the basal conductance. The magnitude of the nystatin-increased conductance was much smaller in the presence (▪) than in the absence of TY23 (□). The NPPB-sensitive current was also much smaller in the presence of TY23 (▪) than in the absence of TY23 (□). n = 5-8.