Comparative effects of oral aromatic and branched-chain amino acids on urine calcium excretion in humans
Comparative effects of oral aromatic and branched-chain amino acids on urine calcium excretion in humans
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DOI：
10.1007/s00198-006-0320-x
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发表时间：
2007-07-01
影响因子：
4
通讯作者：
Dallal, G. E.
中科院分区：
文献类型：
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作者：
Dawson-Hughes, B.;Harris, S. S.;Dallal, G. E.
在 30 名成年人中，与支链氨基酸摄入量的类似增加相比，增加芳香族氨基酸的摄入量会增加钙排泄和血清 IGF-1，但不会增加骨转换指数。所涉及的机制尚不确定，但这些发现表明钙传感器受体的作用。简介与支链氨基酸 (BCAA) 相比，芳香族氨基酸 (AAA) 与钙传感受体 (CaR) 结合，因此影响钙稳态的潜力更大。在本研究中，我们比较了增加 AAA 与 BCAA 摄入量对钙排泄、血清 IGF-1、骨转换标志物以及口服钙负荷后 4 小时钙排泄的影响。方法 采用低蛋白代谢饮食两周后，30 名健康受试者被随机分配，将 AAA 或 BCAA 摄入量增加五倍，为期两周。比较两组钙排泄和其他指标的变化。结果随着氨基酸摄入量的增加，相对于BCAA组，AAA组24小时钙排泄量（P=0.027）、IGF-1（P=0.022）和口服负荷后4小时钙排泄量（P=0.023）显着增加。代谢标志物的组间变化没有显着差异。结论与BCAA相比，AAAs促进钙排泄。钙尿似乎不是由骨吸收增加引起的，而可能是由于钙吸收增加而引起的。 AAA 还增加了 IGF-1 的循环水平。总的来说，这些发现提出了 AAA 可能通过与 CaR 的相互作用选择性影响钙稳态的可能性。
In 30 adults, increasing intake of aromatic amino acids increased calcium excretion and serum IGF-1, but not indices of bone turnover, when compared with similar increases in intake of branched-chain amino acids. The mechanisms involved are not certain but these findings suggest a role for the calcium sensor receptor.Introduction In contrast to branched-chain amino acids (BCAAs), aromatic amino acids (AAAs) bind to the calcium sensing receptor (CaR) and thus have an increased potential to affect calcium homeostasis. In this study we compare the effects of increased intake of AAAs versus BCAAs on calcium excretion, serum IGF-1, markers of bone turnover, and 4-hr calcium excretion after an oral calcium load.Methods After two weeks on low-protein metabolic diets, 30 healthy subjects were randomized to a fivefold increase in intake of AAAs or BCAAs for two weeks. Changes in calcium excretion and other measures were compared in the two groups. Results With the increase in amino acid intake, 24-hr calcium excretion (P= 0.027), IGF-1 ( P= 0.022), and 4-hr calcium excretion after an oral load ( P= 0.023) increased significantly in the AAA relative to the BCAA group. Group changes in turnover markers did not differ significantly.Conclusion In comparison with BCAAs, AAAs promoted calcium excretion. The calciuria does not appear to result from increases in bone resorption and may occur by increasing calcium absorption. The AAAs also increased circulating levels of IGF-1. Collectively these findings raise the possibility that AAAs may selectively influence calcium homeostasis through their interactions with the CaR.