Biological activity of the vitamin D metabolite 1,25-dihydroxycholecalciferol in chickens and rats.
Biological activity of the vitamin D metabolite 1,25-dihydroxycholecalciferol in chickens and rats.
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维生素 D 代谢物 1,25-二羟基胆钙化醇在鸡和大鼠中的生物活性。
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
R. G. Wong
中科院分区：
文献类型：
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作者：
A. Norman;R. G. Wong
维生素D »代谢物1，25-二羟基胆固醇alcif eroi的生物活性在三个实验中的鸡和两个实验中的佝偻病大鼠进行了评估。在官方大鼠品系试验中，发现1，25-二羟基胆钙化醇与等效剂量的胆钙化醇具有相同的活性。在孵化后，每天向白色来航公鸡饲喂20至250皮摩尔（0.01至0.10 μ g）剂量的1，25-二羟基-[26，27-sH]胆钙化醇或标准量的胆钙化醇，持续3周。测量以下维生素D相关反应：a）生长速率; B）体内和c）体外试验剂量的“Cas+”的肠转运; d）骨灰百分比; e）血清钙升高。对于这些测定中的每一个，判断1，25-二羟基胆钙化醇与母体胆钙化醇相比“活性高得多”a）“活性更高”（B，d）和“活性一样”（c，e），其中“活性高得多”是用等效剂量的胆钙化醇获得的2至4倍的响应，“活性更高”是用等效剂量的胆钙化醇获得的1至2倍的响应。在某些情况下（d，e），由1，25-二羟基胆钙化醇介导的反应的相对增量在低剂量水平（20 pmol/天）下比在较高剂量水平（100 pmol/天）下更大。与胆钙化醇相比，每日给药后获得的1，25-二羟基胆钙化醇的相对活性测定值明显低于先前分析这些类固醇单次给药活性时获得的结果。单剂量的1，25-二羟基胆钙化醇在刺激肠内Ca 2+升高方面是胆钙化醇的4.4 ±1.1（SE）倍[Science 171：79（1971）]，在刺激血清Ca 2+升高方面是胆钙化醇的5.5 ±1.4（SE）倍[J. Biol. Chem. 247：5728（1972）]。这些结果共同支持了1，25-二羟基胆钙化醇是迄今已知的最高效形式的维生素D的概念。J.营养102：1709-1718，1972.索引
The biological activity of the vitamin D»metabolite 1,25-dihydroxy cholee alcif eroi was assessed in three experiments in the chick and two experiments in the rachide rat. In the official rat line test 1,25-dihydroxycholecalciferol was found to be equally as active as an equivalent dose of cholecalciferol. Doses of 20 to 250 pmoles (0.01 to 0.10 Mg) of l,25-dihydroxy-[26,27-sH] cholecalciferol or standard amounts of cholecalciferol were fed daily to White Leghorn cockerels for 3 weeks after hatching. The following vitamin D-related responses were measured: a) the rate of growth; b) intestinal transport of test doses of "Cas+ in vivo and c) in vitro; d) percentage bone ash; e) serum calcium elevation. For each of these assays the 1,25-dihydroxycholecalciferol was judged to be "much more active" a) "more active" (b,d), and "as active" (c,e), as the parent cholecalciferol, where "much more active" is a response 2 to 4 times and "more active" is a response 1 to 2 times that obtained with an equivalent dose of cholecalciferol. In some instances (d,e), the relative increment of response mediated by 1,25-dihydroxycholecalciferol was greater at the low dose level (20 pmoles/day) than at a higher dose level (100 pmoles/day). The relative activity determination of 1,25-dihydroxycholecalciferol, obtained after daily administra tion, in comparison with cholecalciferol was markedly less than that previously obtained when the activity of single doses of these steroids were analyzed. A single dose of 1,25-dihydroxycholecalciferol was 4.4 ±1.1 (SE) [Science 171: 79 (1971)] times as effective as cholecalciferol in stimulating the intestinal absorp tion of Ca2+, and 5.5 ±1.4 (SE) [J. Biol. Chem. 247: 5728 (1972)] times as effective as cholecalciferol in stimulating serum Caa+ elevation. These results collectively support the concept that 1,25-dihydroxycholecalciferol is the most highly potent form of Vitamin Ds yet known. J. Nutr. 102: 1709-1718, 1972. INDEXING