Figure 4.
Deletion of neural precursor cell expressed developmentally downregulated 4-2 (Nedd4-2) abolishes the effect of dietary K+ intake on distal convoluted tubule (DCT) membrane potential. A: perforated whole cell recording showing K+ current (IK) reversal potential in the DCT of control mice on normal K+ (NK), high K+ (HK), and low K+ (LK) diets for 7 days, respectively. B: perforated whole cell recording showing IK reversal potential in the DCT of kidney tubule-specific Nedd4-2 knockout (Ks-Nedd4-2 KO) mice on NK, HK, and LK diets for 7 days, respectively (a recording for control mice on NK is indicated). C: scatter graph summarizing the results of experiments in which IK reversal potential was measured in both male mice (blue triangles; n = 8/4/5 patches from 5/3/4 control mice on HK/NK/LK and n = 7/7/4 patches from 4/4/3 Ks-Nedd4-2 KO mice on HK/NK/LK) and female mice (red circles; n = 5/3/5 patches from 4/3/4 control mice on HK/NK/LK and n = 5/5/4 from 4/4/3 Ks-Nedd4-2 KO mice on HK/NK/LK). Mean values and SEs are shown on the left of each column. For the measurement of IK reversal potential, the bath solution contained 140 mM NaCl and 5 mM KCl and the pipette solution has 140 mM KCl. *Significant difference (P < 0.05). Significance was determined by two-way ANOVA. Neddlflox/flox, floxed neural precursor cell expressed developmentally downregulated 4-like mice.