Effect of 1,25-Dihydroxyvitamin D₃ and Diltiazem on Tissue Calcium in Uremic Rat

Abstract

The concentration of calcium was measured in the aorta, heart, and kidney of uremic rats treated with 100 ng/kg/day 1,25-dihydroxyvitamin D₃ (1,25 D₃) or 60 mg/kg/day diltiazem for 12 weeks. The concentration of calcium was increased in the aorta, heart, and kidney of uremic rats, and was further increased by administration of 1,25 D₃ The 1,25 D₃-induced increase in calcium in the aorta was inhibited by diltiazem, but this effect was not accompanied by a decrease in serum calcium x phosphate products. Diltiazem had no effect on the 1,25 D₃-induced increase of calcium in the heart and kidney. Thus, in uremia 1,25 D₃ may promote the calcification of the aorta; calcium antagonists may protect against calcification without a reduction in serum calcium x phosphate products

Key Words:

• Calcium
• Calcium antagonist
• 1,25-Dihydroxyvitamin D₃
• Uremia