Fig. 1.

Ca²⁺ absorption in the thick ascending limb of Henle (TAL). (a) The schematic view of Ca²⁺ reabsorption in the TAL. Paracellin-1 (claudin-16) is located in the tight junction of TAL and serves as the paracellular route for divalent cations. (b) Immunofluorescence image for paracellin-1 (claudin-16) in the mouse TAL cells. Paracellin-1 is co-localized with THP (the marker of TAL) and highly expressed in the tight junction1). BSC1, bumetanide sensitive channel; ROMK, renal outer medullary potassium channel; ClCNKB, chloride channel Kb.