Fig. 4.

Effect of CDCA on I_sc in nystatin-permeablized T84 cells. T84 cells grown in Transwells were mounted in Ussing chambers. Representative tracings of I_sc show CDCA the effect of CDCA on basolaterally (A; n = 4) or apically (B; n = 5) permeablized T84 cells. A: basolateral membranes of T84 cells were permeabilized with nystatin (200 μg/ml) in the presence of an apical to basolateral Cl⁻ gradient. CDCA (500 μM) was added to the basolateral solution, and after the I_sc had stabilized, forskolin (10 μM) was added to the basolateral solution followed by CFTR_inh-172 (10 μM) to the apical solution. B: apical membranes of T84 cells were permeabilized with nystatin in the presence of an apical to basolateral K⁺ gradient. Sequentially ouabain (100 μM), CDCA (500 μM), and carbachol (CCH; 100 μM) were added to the basolateral solution.