FIGURE 6.
Involvement of Epac1-Rap1A-RhoA-ROCK signaling in intestinal Cl− secretion. A, summary of the effects of RhoA inhibitor C3 toxin (1 μg/ml) and ROCK inhibitor H1152 (1 μm) on IK(ap). Confluent T84WT cell monolayers on a permeable support were pretreated with C3 toxin for 4 h in culture media prior to subjecting them to the Ussing chamber experiment and with H1152 for 30 min directly in the chamber. FSK was then added. The results are presented as means ± S.E.; n = 4. B, 8-pCPT-2′-Me-cAMP enhances the insertion of KCNN4c (red) into the membrane (bottom), and this was partially inhibited by ROCK inhibitor H1152 (top). The scale bar represents 10 μm. Confluent T84WT cell monolayers were stimulated with 8-pCPT-2′-O-Me-cAMP for 30 min at 37 °C prior to staining with FITC-WGA (green) on ice, then fixed, and stained for KCNN4c (red). Error bars represent S.E.