Effect of oxalate on the growth of renal tubular epithelial cells

PURPOSE: Until recently, oxalate was considered merely as a major component of calcium oxalate stones, forming crystals in the lumen of the renal tubules. However, new evidence suggests that oxalate is not only a major constituent of calcium oxalate stones but also has effect on renal tubular epithelial cells, affecting the pathogenesis of nephrolithiasis. We tried to elucidate the effect of oxalate on the growth of renal tubular epithelial cells of different species and locations and also to interpret the possible role of the oxalate in the pathogenesis of urolithiasis. MATERIALS AND METHODS: Porcine proximal renal tubular epithelial cells (LLC-PK1) and canine distal renal tubular epithelial cells (MDCK) were incubated with different concentrations of oxalate, and the effect of oxalate on the growth of the cells was assessed by methylthiazoletetrazolium assay. RESULTS: Growth of the renal tubular epithelial cells was inhibited with increasing concentrations of oxalate in both proximal and distal lines. CONCLUSION: Oxalate may cause stone formation by affecting the growth of renal tubular epithelial cells as well as by providing a constituent of calcium oxalate stones.