Metabolism of cadmium, zinc and copper in the rat kidney: the role of metallothionein and other binding sites.
Metabolism of cadmium, zinc and copper in the rat kidney: the role of metallothionein and other binding sites.
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DOI：
10.1289/ehp.845473
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发表时间：
1984-03
影响因子：
10.4
通讯作者：
Fowler B
中科院分区：
文献类型：
--
作者：
Petering DH;Loftsgaarden J;Schneider J;Fowler B
研究了宿主缺锌对镉、锌、铜在雄性大鼠肾细胞浆和未分离细胞球之间和内的分配的影响。试验一：饲喂含镉100微克/毫升的饲料，连续30天。然后，将染镉大鼠和对照组分成两组，分别饲喂锌充足或缺乏的半纯饲料14天。在此方案后，以微克Cd/g蛋白为基础，胞浆和超声处理的未分离颗粒的上清液中总Cd和金属硫蛋白结合Cd的浓度是相当的。虽然不到5%的胞质Cd不与金属硫蛋白(MT)结合，但颗粒组分中存在的非MT Cd是MT的3-5倍。缺锌日粮增加了颗粒饲料中非MT Cd的含量。用Sephadex G-75柱层析法定量测定了铜、锌在Sephadex G-75柱层析金属谱的高分子量、超氧化物歧化酶和金属硫蛋白区域的分布。在镉暴露和饲喂正常锌(锌+)日粮的动物中，上清液和颗粒金属含量仅在MT部分发生变化。同样，缺锌主要影响与金属硫蛋白结合的金属的补充：锌显著减少，铜降低的幅度较小。镉没有变化。对照肾脏，未暴露于Cd，通常含有相当数量的锌、CuMT。缺锌两周会大大降低MT-锌和铜的含量，但不会改变其他细胞池的金属含量。
Studies were undertaken to determine the effect of host zinc deficiency upon the distribution of Cd, Zn and Cu between and within male rat kidney cytosol and unfractionated cell pellet. In the first experiment male rates were fed stock diets supplemented with 100 micrograms Cd/mL in the drinking water for 30 days. Then Cd-treated rats and controls were segregated into groups, which received semipurified diets adequate or deficient in zinc for 14 days. After this regimen there were comparable concentrations of total Cd and metallothionein bound Cd in cytosol and the supernatant of sonicated, unfractionated pellet on a microgram Cd/g protein basis. Although less than 5% of cytosolic Cd is not bound to metallothionein (MT), 3-5 times as much non-MT Cd is present in the particulate fraction. The zinc-deficient (Zn-) dietary regime increases the non-MT Cd in the pellet. Quantitations were done of the Cu and Zn distribution in high molecular weight, superoxide dismutase, and metallothionein regions of the profiles of metals from Sephadex G-75 chromatography. In animals exposed to Cd and fed a zinc-normal (Zn+) diet, supernatant and pellet metal contents only change in the MT fraction. Similarly, zinc deficiency affects primarily the complement of metals bound to metallothionein: zinc is markedly decreased and Cu is lowered to a smaller extent. Cadmium is unchanged. Control kidney, unexposed to Cd, normally contains a substantial amount of Zn,CuMT. Two-week zinc deficiency greatly reduces MT-Zn and -Cu content without altering the metal content of other cellular pools.(ABSTRACT TRUNCATED AT 250 WORDS)