Fig. 1.

Architecture of rat nephron and collecting duct showing segmental localization of major transporters and channels that play critical roles in water and solute reabsorption (modified from [55]). AQP1, AQP2, AQP3 and AQP4 Aquaporin water channel isoforms 1 through 4, NHE3 sodium–hydrogen exchanger isoform 3, UT-A1 and UT-A2 urea transporter isoforms A1 and A2, BSC1 bumetanide-sensitive cotransporter-1, ROMK renal outer medullary potassium channel, TSC1 thiazide-sensitive cotransporter-1, ENaC epithelial sodium channel