Fig. 2.

Glucose transporters in the renal proximal tubule. Data suggest approximately 90% of filtered glucose is reabsorbed in the first part (S1) of the proximal tubule and is mediated by SGLT2. The remaining 10% is reabsorbed in the distal (S2/S3) part of the tubule and this is mediated by SGLT1. This process is extremely efficient and virtually no glucose escapes into the urine of a healthy individual. Glucose is returned to the bloodstream via GLUT2 in the S1/S2 segment and via GLUT1 in the S3 segment of the proximal tubule