Remodeling of the collecting duct.

<p>Kidneys from mice left untreated (sucrose, control) or receiving KCl, NaHCO₃ or NH₄Cl for 7 days were sectioned and stained for specific cell markers (AE1 for type A intercalated cells, pendrin for non-type A intercalated cells, and calbindin D28k and AQP2 for principal cells). The relative number of cells expressing these markers was counted for the different segments of the collecting system. CNT connecting tubule, CCD cortical collecting duct, OMCD outer medullary collecting duct, _iIMCD initial inner medullary collecting duct, *<i>p</i>≤0.05, ***<i>p</i>≤0.001.