Almost all of the glucose entering glomeruli in the afferent glomerular arterioles is filtered into the nephron fluid of the proximal renal tubules. Most (up to 90%) of this filtered glucose is reabsorbed in the initial proximal convoluted segment (S1) by SGLT2 located at the luminal surface of proximal tubular cells. Remaining glucose is reabsorbed from the filtrate in themore distal convoluted and straight segments by SGLT1. Glucose within the proximal tubular cells is then transported back to the interstitial compartment and thence to the plasma by the facilitative glucose transporters GLUT2 in the S1 segment, respectively. In normal individuals with an average plasma glucose concentration of 5-5.5 mmol/L (90-100mg/dL), approximately 160–180 g of glucose is filtered daily, with less than 0.5 g/day of glucose appearing in the urine based on Bakris et al. and Bays.
