Erythrocyte metallothionein as an index of zinc status in humans.
Erythrocyte metallothionein as an index of zinc status in humans.
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红细胞金属硫蛋白作为人类锌状态的指标。
DOI：
10.1073/pnas.87.4.1259
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发表时间：
1990
影响因子：
11.1
通讯作者：
Cousins,RJ
中科院分区：
文献类型：
--
作者：
Grider,A;Bailey,LB;Cousins,RJ
用ELISA法测定了受试者红细胞裂解物中金属硫蛋白的浓度。以注射人金属硫蛋白-1的绵羊血清中提取的免疫球蛋白为竞争试剂，建立了人金属硫蛋白-1抗体的竞争分析方法。受试者在驯化3天后，给予半纯缺锌饮食(每公斤饲料含锌0.7毫克)8天的耗竭期。空腹血浆锌浓度降低了约7%。在耗竭期结束时，红细胞裂解物中的金属硫蛋白显著降低到初始水平的59%。这些精疲力竭的受试者补充锌(50毫克)在24小时内没有增加红细胞金属硫蛋白水平。对照组每天补充锌(50毫克/天)，红细胞金属硫蛋白在7天内达到最大值的7倍。这些水平在停止补锌后14天内下降了61%。大鼠[35S]金属硫蛋白与人红细胞裂解液孵育显示，在20%三氯乙酸中的35S可溶性随时间而增加，这表明标记蛋白的降解可能是通过裂解液中的蛋白酶活性来实现的。提示补锌可诱导红细胞金属硫蛋白的生成，而低锌摄入量可减少网织红细胞/红细胞中金属硫蛋白的合成和/或加速蛋白质的降解。红细胞中的金属硫蛋白水平可以提供一个有用的指标来评估人类的锌状况。
Metallothionein concentrations in erythrocyte lysates derived from human subjects were measured by an ELISA procedure. IgG obtained from serum of sheep injected with human metallothionein 1 was used in this competitive assay. Subjects were fed a semipurified zinc-deficient diet (0.7 mg of zinc per kg of diet) for an 8-day depletion period after 3 days of acclimation. Fasting plasma zinc concentrations were reduced approximately 7%. Metallothionein in the erythrocyte lysates was significantly decreased to 59% of the initial level by the end of the depletion period. Supplementation of these depleted subjects with zinc (50 mg) did not increase erythrocyte metallothionein levels within 24 hr. Daily supplementation of control subjects with zinc (50 mg/day) increased erythrocyte metallothionein to a 7-fold maximum within 7 days. These levels were reduced by 61% within 14 days after zinc supplementation was terminated. Incubation of rat [35S]metallothionein with human erythrocyte lysate showed a time-dependent increase in 35S soluble in 20% trichloroacetic acid, indicating degradation of the labeled protein, presumably via protease activity in the lysate. It is proposed that zinc supplementation induces erythrocyte metallothionein during erythropoiesis and that low zinc intake decreases synthesis and/or accelerates degradation of the protein in reticulocytes/erythrocytes. Metallothionein levels in erythrocytes may provide a useful index upon which to assess zinc status in humans.