Frolik C A, DeLuca H F
J Clin Invest. 1973 Mar;52(3):543-8. doi: 10.1172/JCI107214.
Daily oral administration of 1,25-dihydroxycholecalciferol to vitamin D-deficient rats increases the rate of disappearance of [(3)H]1,25-dihydroxycholecalciferol and increases the rate of appearance of metabolites both less polar and more polar than 1,25-dihydroxycholecalciferol in the intestine, bone, liver, kidney, plasma, and muscle. Since 1,25-dihydroxycholecalciferol is believed to be the metabolically active form of vitamin D in the stimulation of intestinal calcium transport and bone calcium mobilization, these results provide an explanation for the fact that daily oral administration of 1,25-dihydroxycholecalciferol is relatively ineffective in the maintenance of serum calcium and in the calcification of bone in rats.
每日给维生素D缺乏的大鼠口服1,25 - 二羟胆钙化醇,会增加[(3)H]1,25 - 二羟胆钙化醇在肠道、骨骼、肝脏、肾脏、血浆和肌肉中的消失速率,并增加比1,25 - 二羟胆钙化醇极性更小和更大的代谢产物的出现速率。由于1,25 - 二羟胆钙化醇被认为是维生素D在刺激肠道钙转运和骨钙动员方面具有代谢活性的形式,这些结果解释了以下事实:每日给大鼠口服1,25 - 二羟胆钙化醇在维持血清钙水平和促进大鼠骨骼钙化方面相对无效。