Figure 7.

(a) Effect of different blockers in nystatin-permeabilized rat distal colon (200 mg nystatin l⁻¹). 293B (30 μM) and Gadoliniumchloride (100 μM) were applied to the serosal side, NPPB (100 μM) and DPC (1 mM) to the mucosal side of the tissue. (b) Effect of quercetin (100 μM), added to the serosal bath 20 min after the blockers in the same experiments. The experiments with Gd³⁺ and the respective controls were performed in HEPES/Tris-buffer. Black bars represent the control experiments without the blocker. Numbers in parentheses indicate the number of experiments. *P<0.05, **P<0.001 versus respective controls.