Effects of Magnesium Deficiency, Dietary Sulfate and Thyroxine Treatment on Kidney Calcification and Tissue Protein-bound Carbohydrate in the Rat

Abstract

Three experiments were conducted to investigate relationships between calcium accumulation in the kidney and changes in ground substrance of the magnesium-deficient young male albino rat. It was found that a modest dietary sulfate deficiency did not prevent kidney calcification, nor did it prevent the lowered liver protein-bound hexose/hexosamine ratio of magnesium-deficient animals. Dietary L-thyroxine (L-T4) prevented kidney calcification, lowered total serum protein and the percentage of glycoprotein in the serum protein. Magnesium deficiency lowered total protein in serum but not glycoprotein content of the serum protein. Retention of 35S in serum and bone 48 hours after dosing was decreased by magnesium deficiency and especially by L-T4 treatment. Kidney 35S retention 48 hours after a single dose was greater in animals fed a magnesium-deficient diet for 14 days than for 4 days except in L-T4 treated animals. Kidney calcification and 35S retention were not affected by intraperitoneal dosage with D-T4. On the basis of these experiments it appears that the initial stages of kidney calcification arising from magnesium deficiency do not involve changes in ground substance, although such changes may contribute to the later, more extensive calcification.