Rat renal 25-hydroxyvitamin D3 1- and 24-hydroxylases: their in vivo regulation.
Rat renal 25-hydroxyvitamin D3 1- and 24-hydroxylases: their in vivo regulation.
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大鼠肾 25-羟基维生素 D3 1- 和 24- 羟化酶：它们的体内调节。
DOI：
10.1152/ajpendo.1984.246.2.e168
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
DeLuca,HF
中科院分区：
文献类型：
--
作者：
Tanaka,Y;DeLuca,HF
研究了甲状腺甲状旁腺切除术、甲状旁腺激素、1，25-二羟维生素D3、膳食钙、膳食磷、年龄和性别对大鼠肾脏25-羟基维生素D3 1-和24-羟化酶的影响。甲状腺甲状旁腺切除术的维生素D缺乏大鼠废除25-羟基维生素D3 1-羟化酶的活性，和牛甲状旁腺提取物的甲状腺甲状旁腺切除大鼠恢复减少1-羟化酶活性的管理。酶活性的抑制和恢复都需要许多小时（18-24小时），而不依赖于血清钙和无机磷水平的快速变化。给予维生素D缺乏大鼠1，25-二羟维生素D3，在48小时内抑制25-羟维生素D3 1-羟化酶活性并刺激25-羟维生素D3 24-羟化酶活性。维持低钙或低磷饮食并每日补充20 IU维生素D3的大鼠与类似治疗但喂食含有足够钙或足够磷的饮食的大鼠相比，显示出高的25-羟基维生素D3 1-羟化酶活性和低的24-羟化酶活性。当维生素D充足的大鼠肾25-羟基维生素D3 1-羟化酶活性受到抑制，放置在低钙维生素D缺乏的饮食7天，1-羟化酶活性大大刺激6周龄大鼠，但少得多，所以随着年龄的增长。
The effects of thyroparathyroidectomy, parathyroid hormone, 1,25-dihydroxyvitamin D3, dietary calcium, dietary phosphorus, age, and sex on the renal 25-hydroxyvitamin D3 1- and 24-hydroxylases measured in vitro in rats have been studied. Thyroparathyroidectomy of vitamin D-deficient rats abolishes 25-hydroxyvitamin D3 1-hydroxylase activity, and administration of bovine parathyroid extract to the thyroparathyroidectomized rat restores diminished 1-hydroxylase activity. Both suppression and restoration of the enzyme activities require many hours (18-24 h) independent of rapid changes in serum calcium and inorganic phosphorus levels in response to these manipulations. Administration of 1,25-dihydroxyvitamin D3 to vitamin D-deficient rats suppresses 25-hydroxyvitamin D3 1-hydroxylase activity and stimulates 25-hydroxyvitamin D3 24-hydroxylase activity within 48 h. Rats maintained on a low-calcium or a low-phosphorus diet with a daily supplement of 20 IU vitamin D3 show high 25-hydroxyvitamin D3 1-hydroxylase activity and low 24-hydroxylase activity as compared with rats similarly treated but fed a diet containing adequate calcium or adequate phosphorus. When vitamin D-sufficient rats having suppressed renal 25-hydroxyvitamin D3 1-hydroxylase activity are placed on a low-calcium vitamin D-deficient diet for 7 days, the 1-hydroxylase activity is greatly stimulated in 6-wk-old rats but much less so in rats with advancing age.