Calcium Oxalate Excretion and Hematuria in Vitamin B6-Deficient Rats Fed Phthalylsulfathiazole

Abstract

Weanling male albino rats were fed a vitamin B₆-deficient diet containing 0.5% of phthalylsulfathiazole for periods up to 9 weeks. Profuse urinary excretion of calcium oxalate crystals occurred in all animals, and gross hematuria was common. Many of the rats receiving less than about 0.35 µg of the vitamin per gram of diet showed some degree of hydronephrosis and several had ureteral calculi. Histological studies showed the hematuria originated around foci of crystal deposition in the pelvis of the kidney with or without an associated hydronephrosis. Calcium oxalate excretion, but no crystal deposition in the kidney, kidney damage or hematuria occurred when the deficient diet minus phthalylsulfathiazole was fed. A vitamin B₆ level of 1.57 µg per gram of diet, which is about 50% higher than the generally accepted level required for growth, did not prevent the excretion of calcium oxalate crystals in some rats. Supplementation with 5 µg of pyridoxine hydrochloride per gram of diet prevented urinary excretion of calcium oxalate crystals and was effective in preventing kidney damage and hematuria when phthalylsulfathiazole was fed. The crystal deposits in the kidney contained sulfathiazole and the results of the experiments cited above indicate that the excretion of this compound in vitamin B₆-deficient rats was directly associated with renal damage and hematuria.