Evidence that calcitonin stimulates 1,25-dihydroxyvitamin D production and intestinal absorption of calcium in vivo.
Evidence that calcitonin stimulates 1,25-dihydroxyvitamin D production and intestinal absorption of calcium in vivo.
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有证据表明降钙素可刺激体内 1,25-二羟基维生素 D 的产生和肠道对钙的吸收。
DOI：
10.1172/jci112597
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Hayslett,JP
中科院分区：
文献类型：
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作者：
Jaeger,P;Jones,W;Clemens,TL;Hayslett,JP
虽然已经确定甲状旁腺激素和磷酸盐是1,25-二羟基维生素D [1,25(OH)2D]产生的重要调节因子，但降钙素是否影响体内维生素D代谢尚不清楚。在大鼠实验中测定慢性降钙素输注（0.2 U X h-1）对血浆维生素D代谢物水平和钙代谢的影响。切除甲状旁腺的动物被喂食含钙或无钙的饮食，研究时间长达2周，然后将其杀死。在对照大鼠中，单独无钙饮食12天导致125 (OH)2D水平从24 +/- 5增加到139 +/- 37 pg。ml-1, P = 0.025。与常规饮食的对照组相比，降钙素的输注也刺激了1,25(OH)2D水平（80 +/- 17 vs 38 +/- 6 pg）。ml-1, P < 0.05)和无钙饮食（460 +/- 50比139 +/- 37 pg）。ml-1, P < 0.001)。此外，降钙素使正常饮食的动物血浆钙水平提高了50%；这种效果很可能是由于肠道对钙的吸收增加，因为从饮食中去除钙会明显减弱这种效果。相反，降钙素给药对25(OH)D血浆水平没有显著影响。总的来说，这些数据表明降钙素和钙是125 (OH)2D生成的独立调节剂，降钙素通过增加循环中的125 (OH)2D水平来刺激肠道对钙的吸收。图片
Although it is well established that parathyroid hormone and phosphate are important regulators of 1,25-dihydroxyvitamin D [1,25(OH)2D] production, it remains unclear whether calcitonin affects vitamin D metabolism in vivo. Experiments were performed in the rat to determine the effect of chronic calcitonin infusion (0.2 U X h-1) on plasma levels of vitamin D metabolites and on calcium metabolism. Thyroparathyroidectomized animals fed a calcium-replete or calcium-free diet were studied for as long as 2 wk before they were killed. In control rats, a calcium-free diet alone for 12 d resulted in an increase in 1,25(OH)2D levels from 24 +/- 5 to 139 +/- 37 pg . ml-1, P = 0.025. The infusion of calcitonin also stimulated 1,25(OH)2D levels compared with controls on a regular diet (80 +/- 17 vs. 38 +/- 6 pg . ml-1, P less than 0.05) and on a calcium-free diet (460 +/- 50 vs. 139 +/- 37 pg . ml-1, P less than 0.001). In addition, calcitonin increased plasma calcium levels in animals on a regular diet by 50%; this effect was most likely due to increased intestinal absorption of calcium, because removal of calcium from the diet markedly blunted this effect. In contrast, calcitonin administration did not significantly affect 25(OH)D plasma levels. Collectively, these data suggest that calcitonin and calcium are independent regulators of 1,25(OH)2D production and that calcitonin stimulates intestinal absorption of calcium, by increasing circulating levels of 1,25(OH)2D.Images