Garabedian M, Holick M F, Deluca H F, Boyle I T
Proc Natl Acad Sci U S A. 1972 Jul;69(7):1673-6. doi: 10.1073/pnas.69.7.1673.
Thyroparathyroidectomy of rats on a diet low in calcium reduces production of 1,25-dihydroxycholecalciferol from 25-hydroxycholecalciferol to negligible levels within 40 hr, and increases production of another metabolite, called Va. Parathyroid extract, at a dose of 20 units per day, prevents these changes. When 40 units per day of parathyroid extract is given 48 hr after thyroparathyroidectomy, 1,25-dihydroxycholecalciferol production is restored almost to control levels within 36 hr. The change brought about by parathyroid extract cannot be attributed to resulting changes in serum calcium or phosphorus concentration. It appears that the parathyroid hormone serves as a tropin for production of 1,25-dihydroxycholecalciferol, the hormonal form of vitamin D responsible for calcium mobilization from intestinal contents and bone.
给食用低钙饮食的大鼠进行甲状腺甲状旁腺切除术后,在40小时内,从25-羟基胆钙化醇生成1,25-二羟基胆钙化醇的过程减少到可忽略不计的水平,并增加了另一种称为Va的代谢产物的生成。甲状旁腺提取物,每天剂量为20单位,可防止这些变化。在甲状腺甲状旁腺切除术后48小时给予每天40单位的甲状旁腺提取物,1,25-二羟基胆钙化醇的生成在36小时内几乎恢复到对照水平。甲状旁腺提取物引起的变化不能归因于血清钙或磷浓度的相应变化。甲状旁腺激素似乎作为一种促激素,促进1,25-二羟基胆钙化醇的生成,1,25-二羟基胆钙化醇是维生素D的激素形式,负责从肠道内容物和骨骼中动员钙。