Cellular mechanisms in renal tubular transport of divalent inorganic anions

The kidney is a key organ in the homeostasis of inorganic phosphate (P-i) and sulfate (S-i). These anions are freely filtered at the glomerular capillaries and are then reabsorbed in the proximal tubule. Studies on isolated membrane vesicles allowed the identification of Na/phosphate and Na/suifate-cotransporters. Subsequently these transporters have been cloned. Vesicle studies documented that physiological (and pathophysiological) alterations involve regulated transport rates of these cotransporters. Molecular studies using cDNA-probes and specific antibodies indicated that physiological regulation occurs at multiple cellular levels (e.g. transcription/translation and membrane traffic).