Fig. 12.
Effect of the PKC inhibitor GF109203X on the open probability (Po) of Xenopus ENaC. A: a 10-min baseline recording of ENaC activity (control to control end) shows typical channel run-down. GF109203X was added to the apical bath solution, and Xenopus ENaC activity was monitored for several minutes after the control recording. The addition of 0.4 μM GF109203X resulted in the recovery of ENaC activity, as measured at the level of Po of the channels. B: representative Western blot of 3 independent experiments showing protein levels of MARCKS after Xenopus 2F3 cells were treated with vehicle (MOCK), PKC inhibitor (GF109203X) for 5 min, then PKC activator (PMA) for an additional 15 min, or PMA alone for 15 min. The top band of the doublet represents the phosphorylated form of MARCKS. C: representative Western blot corresponding to B showing total actin protein as a loading control. D: densitometric analysis of B and C showing the PMA-induced increase in phospho MARCKS protein is blocked by treatment with the PKC inhibitor GF109203X. Values are means ± SE (*P < 0.05).