Thiazide/amiloride (T+Am) and acetazolamide (Acz) reduce lithium (Li+) -induced downregulation of AQP2 in Li-NDI mice. (A–D) Immunoblot and corresponding densitometric analyses of AQP2 of mouse kidneys that are untreated (control [Ctr]), treated with Li+ only, or treated with Li+ together with Acz or T+Am. (B and D) The signals for AQP2 are densitometrically quantified. Mean values±SEMs of normalized AQP2 abundance are given relative to Ctr. Equal loading of the samples was confirmed by staining of the blots with Coomassie blue (Cm). One-way ANOVA and Bonferroni multiple comparison test. *Significant differences (P<0.05) from Ctr. Paraffin sections of immersion-fixed kidneys from (A, E, and I) Ctr, (B, F, and J) Li+-treated, (C, G, and K) Li++T+Am-treated, and (D, H, and L) Li++Acz-treated mice were incubated with a rabbit polyclonal AQP2 antibody followed by a Cy3–coupled goat anti–rabbit IgG. (A–D) Overviews and high magnifications of representative (E–H) connecting tubules (CNTs) and (I–L) cortical collecting ducts (CCDs).