Increased urinary excretion of 3-hydroxyisovaleric acid and decreased urinary excretion of biotin are sensitive early indicators of decreased biotin status in experimental biotin deficiency
Increased urinary excretion of 3-hydroxyisovaleric acid and decreased urinary excretion of biotin are sensitive early indicators of decreased biotin status in experimental biotin deficiency
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DOI：
10.1093/ajcn/65.4.951
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发表时间：
1997-04-01
影响因子：
7.1
通讯作者：
Mock, DM
中科院分区：
文献类型：
--
作者：
Mock, NI;Malik, MI;Mock, DM
为了评估生物素状态的各种指标的效用，在正常成年人中实验诱导边缘生物素缺乏。10名受试者食用含有足够抗生物素蛋白的饮食，以结合比饮食中多7倍的生物素。在饮食开始前收集血液和24小时尿液样品，此后每周两次，共20天。尿排泄和血清浓度的生物素及其两个主要的非活性代谢产物bisnorbiotin和生物素亚砜测定后，HPLC分离与亲和素结合试验。尿中3-羟基异戊酸的浓度，生物素依赖性酶的活性降低的指标，通过气相色谱-质谱定量。3-羟基异戊酸的尿排泄量显著增加（P < 0.0001）。对于所有受试者，生物素和双降生物素的尿排泄量均显著降低（P < 0.0001）。相比之下，生物素的平均血清浓度未显著降低（P = 0.06）。这些数据提供的证据表明，3-羟基异戊酸的尿排泄和生物素的尿排泄是生物素缺乏的早期和敏感的指标，而生物素的血清浓度不是。
To assess the utility of various indicators of biotin status, marginal biotin deficiency was induced experimentally in normal adults. Ten subjects consumed a diet that contained enough avidin to bind seven times more biotin than that in the diet. Blood and 24-h urine samples were collected before the diet began and twice weekly thereafter for 20 d. The urinary excretion and serum concentration of biotin and its two principal inactive metabolites bisnorbiotin and biotin sulfoxide were determined after HPLC separation with an avidin-binding assay. The urinary concentration of 3-hydroxyisovaleric acid, an indicator of reduced activity of a biotin-dependent enzyme, was quantitated by gas chromatography-mass spectrometry. The urinary excretion of 3-hydroxyisovaleric acid increased significantly (P < 0.0001). For all subjects, the urinary excretion of both biotin and bisnorbiotin decreased significantly (P < 0.0001 for each). In contrast, the mean serum concentration of biotin did not decrease significantly (P = 0.06). These data provide evidence that the urinary excretion of 3-hydroxyisovaleric acid and the urinary excretion of biotin are early and sensitive indicators of biotin deficiency and that the serum concentration of biotin is not.