<prompt> Maximum reabsorption of sodium takes place inProximal convoluted tubuleDistal convoluted tubuleLoop of HenleCollecting duct  <response>: A Proximal convoluted tubule Transport Proteins Involved in the Movement.of Na and CI-Across the Apical Membranes of Renal Tubular Cells.3SiteApical TransporterFunctionProximal tubuleNaglucose CTNa uptake, glucose uptake NaPi CTNa uptake, Pi uptake Na amino acid CTNa uptake, amino acid uptake Nalactate CTNa uptake, lactate uptake NaH exchangerNa uptake, H extrusion CIbase exchangerCI- uptakeThick ascending limbNa-K-2CI CTNa uptake, CI- uptake, K uptake NaH exchangerNa uptake, H extrusion K channelsK extrusion recyclingDistal convoluted tubuleNaCI CTNa uptake, CI- uptakeCollecting ductNa channel ENaCNa uptake In the proximal tubules, the thick portion of the ascending limb of the loop of Henle, the distal tubules, and the collecting ducts, Na moves by cotransport or exchange from the tubular lumen into the tubular epithelial cells down its concentration and electrical gradients and is actively pumped from these cells into the interstitial space. Thus, Na is actively transported out of all parts of the renal tubule except the thin portions of the loop of Henle. Na is pumped into the interstitium by Na-K ATPase. It extrudes three Na in exchange for two K that are pumped into the cell. 