Palmitate Stimulates the Epithelial Sodium Channel by Elevating Intracellular Calcium, Reactive Oxygen Species, and Phosphoinositide 3-Kinase Activity

Figure 4

NaHS abolishes palmitate-induced oxidative stress and ENaC activation. (a and c) Confocal microscopy images of A6 cells loaded with DCF, an ROS indicator, before and either after application of palmitate (0.3 mM) first, then NaHS (0.1 mM), or after application of NaHS (0.1 mM) first, then palmitate (0.3 mM), to the cells. (b and d) Summary plots of fluorescent intensity under each condition as indicated. Data are from six independent paired experiments ( for each individual experimental set; , compared with the control group). (e) Representative ENaC single-channel current recorded from two A6 cells before and either after addition of 0.3 mM palmitate first, then 0.1 mM NaHS (upper trace), or after addition of 0.1 mM NaHS first, then 0.3 mM palmitate, to the basolateral bath. (f) Summarized ENaC _O under each condition, as indicated ( for each individual experimental treatment; , compared with the control treatment group).

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