Figure 8.

Colocalization of claudin (CLDN)19 and zonula occludens-1 (ZO-1) in human, mouse, and rat kidneys. CLDN19 was colocalized with ZO-1 in human (A and B), mouse (C–F), and rat (G–J) kidneys. Colabeling on kidney sections with uromodulin (UMOD), Na⁺-K⁺-2Cl⁻ cotransporter (NKCC2), Na⁺-Cl⁻ cotransporter (NCC), Na⁺/Ca²⁺ exchanger (NCX1), aquaporin-2 (AQP2), or Cl⁻/${\text{HCO}}_3^{-}$ anion exchanger isoform 1 (AE1) was performed. CLDN19 was expressed at the tight junction (TJ) in the thick ascending limb of Henle’s loop in humans (A), mice (C), and rats (G). CLDN19 was expressed at TJs in the distal convoluted tubule in mice (D) and rats (H). CLDN19 was expressed at a few TJs in the mouse connecting tubule (E) not in the rat connecting tubule (I). CLDN19 was not expressed at TJs in human (B), mouse (F), and rat cortical collecting ducts (J). Scale bars = 50 µm.