Effect of vitamin E and mannitol on renal calcium oxalate retention in experimental nephrolithiasis

The calcium oxalate stone formation is induced in rats by a single injection of sodium oxalate (i.p., 7 mg/100 g body weight). There was increase in kidney oxalate concentration and kidney mitochondrial oxalate binding activity with increased lipid peroxidation. Histopathological observations showed larger aggregates of calcium oxalate crystals in the renal tubules. At 12 hours after oxalate administration a maximal crystal deposition in the renal tubule with denuded epithelium, lymphocytic infiltration and blood were observed. Increased blood urea and creatinine indicated kidney failure after oxalate administration. Calcium oxalate crystalluria, hematuria, and proteinuria with casts were observed. Renal antioxidants vitamin E, ascorbic acid and glutathione were significantly decreased on oxalate challenge. Pretreatment with vitamin E provided only partial protection from calcium oxalate deposition. Pretreatment with vitamin E and mannitol together protected the renal tubules completely from calcium oxalate deposition by normalizing the tissue oxalate concentration and mitochondrial oxalate binding activity and increasing the concentration of antioxidants on oxalate challenge.