Physiological functions renal proximal tubule

Tyson CA, Dabbs IE, Cohen PM, Green CE, Melnick R (1990) Studies of nephrotoxic agents in an improved renal proximal tubule system. Toxicol in Vitro 4-5 403 108 Ullrich KJ, Greger R (1985) Approaches to the study of tubule transport functions. In Seldin DW, Giebisch G (eds) Physiology and Pathophysiology. Raven Press, New York, pp 427 169... 

Oxalate is excreted primarily by the kidney. Oxalate is freely filtered at the glomerulus, where its concentration is normally 1 5 pM. One of the few physiologic functions of oxalate occurs in the proximal tubule where it plays a role in transcellular reabsorption of chloride (mainly present as sodium chloride). Cl entry across the apical membrane is mediated by Cl /oxalate exchange (oxalate is recycled from the tubular lumen to the cell by oxalate/ sulfate exchange, in parallel with Na /sulfate cotransport) [4]. Early studies of renal oxalate clearance using radio-labeled oxalate showed secretion in almost all subjects studied. More recent studies using direct measurement of serum and urine... 

---