Abstract
The proximal tubule plays a central role in the regulation of extracellular volume since it is responsible for roughly two-thirds of the reabsorption of the sodium filtered in the glomeruli. In the proximal tubule, the principal apical membrane pathway for reabsorption of Na+ and secretion of H+ is Na+-H+ exchange mediated by the isoform 3 of the exchanger Na+/H+ (NHE3). The activity of N…