Kidney sections and fixed cells were immunostained as described previously [10 (link)]. For immunochemical staining, sections were stained with anti-AQP2 (Cat. No. AQP-002; Alomone Laboratories) antibody. Hematoxylin was used for counter-staining. For immunofluorescence, the following antibodies were used: anti–acetylated (ac)-α-tubulin (Cat. No. T7451; Sigma-Aldrich), anti–Na/K-ATPase (Cat. No. ab76020; Abcam), anti-AQP1 (Cat. No. AQP-001; Alomone Laboratories), and anti-AQP2 (Cat. No. AQP-002). To detect cell nuclei, DAPI was applied to samples. Images were captured using a Leica microscope (DM2500; Wetzlar).