Figure 8.

Effect of CaMKII inhibition on phospho-NCC protein expression and NCC activity. (A) Western blot from the samples of three independent experiments (N = 3) in which mDCT15 cells were treated with the vehicle (MOCK) or the CaMKII inhibitor KN93 for 4 h before harvesting the cells for protein and isolating the membrane fraction. Blots probed with a phospho-NCC-specific antibody showed an increase in the phospho-NCC protein expression. (B) Summary bar graph of the densitometric analysis for the Western blot in panel (A). The band intensities were quantified after normalizing the immunoreactive bands in the Western blot for phospho-NCC to a Western blot for actin. (C) The effect of the pharmacological inhibition of CaMKII, KN93, on NCC activity in mDCT15 cells. The cells were treated with either the vehicle control (DMSO), 0.05 μM KN93, 0.5 μM KN93, or 5 μM KN93 for 4 h prior to the measurement of the thiazide-sensitive ²²Na⁺ uptake. The thiazide-sensitive ²²Na⁺ uptake was calculated as the difference between the uptakes with and without thiazide. Four independent experiments were performed, N = 4. * represents p < 0.05.