<prompt> Various solutes are reabsorbed in the proximal tubule during tubular reabsorption. Which of the following ion is exchanged for H in proximal convoluted tubule?KNaHC03CI-  <response>: NaH exchanger NHE3 is located in the luminal membrane of the proximal tubule epithelial cell. This transpo system allows Na to enter the cell from the tubular lumen in exchange for a proton H from inside the cell. As in all poions of the nephron, NaK-ATPase in the basolateral membrane pumps the reabsorbed Na into the interstitium so as to maintain a low intracellular Na concentration. The H secreted into the lumen combines with bicarbonate HCO3- to form H2CO3 carbonic acid. Ref: Ives H.E. 2012. Chapter 15. Diuretic Agents. In B.G. Katzung, S.B. Masters, A.J. Trevor Eds, Basic Clinical Pharmacology, 12e. 