Schematic diagram representing the flux of GSH into the renal cells. GSH can enter renal cells by different pathways. Plasma GSH enters renal proximal tubular cells by specific carriers, Oat3 being one of the most representative. The lumen side of the tubular cells is rich in γ-GT that cleaves GSH into CysGly and glutamate. CysGly can be then degraded to the two constitutive amino acids by a dipeptidase. The cysteine (and other amino acids) can be reabsorbed into lumen tubular cells by specific transporters and GSH de novo resynthesized. The two pathways concur to maintain cellular levels of GSH.