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[目的]观察镉(Cd)染毒后锌(Zn)或铜(Cu)诱导肝脏金属硫蛋白(MT)结合锌镉比值(Zn/Cd)与铜镉比值(Cu/Cd)的关系及其意义。[方法]将28只雄性Wistar大鼠随机分为7组,每组4只,分别为:空白对照组(0),不做任何处理;非预处理组(A1、A2),皮下注射生理盐水;Zn处理组(B1、B2),皮下注射ZnCl(每千克体重染Zn25mg);Cu处理2组(C1、C2),皮下注射CuSO(每千克体重染Cu 12.5mg)。预处理24h后,为实验组动物皮下注射镉-金属硫蛋白(CdMT,Cd-4metallothionein),造成Cd急性中毒,其中A1、B1、C1组每千克体重染Cd0.1mg,A2、B2、C2组每千克体重染Cd0.4mg。24h后处死,取肝脏,制备匀浆。离心后取上清液,加入Sephadex G-75色谱层析柱。[结果]空白对照组动物肝脏中与MT结合的最主要金属元素是Zn,而Cd、Cu含量在检测限以下;与前者相比,A1、A2组动物肝脏MT和Cd含量随染毒剂量增加而升高,且A1、A2组肝脏MT中Zn/Cd值分别为20.0和10.0;B1、B2组肝脏MT中Zn/Cd值分别为20.8和20.3,Cu离子未检出;C1、C2组肝脏MT的Cu/Cd值分别为80.0和36.5,Zn含量下降明显。[结论]不同剂量Cd染毒后,Zn或Cu诱导动物肝脏MT中金属含量比例存在差异,Cu/Cd值高于Zn/Cd值,即与MT结合的Cd相比,Cu更易取代与MT结合的Zn。另外,肝脏中非MT结合Zn也是影响与MT结合的金属离子稳态的重要因素。
[Objective] To observe the relationship between the ratio of zinc / cadmium (Zn / Cd) and the ratio of copper to cadmium (Cu / Cd) induced by zinc (Zn) or copper (Cu) in cadmium (Cd) significance. [Methods] 28 male Wistar rats were randomly divided into 7 groups with 4 rats in each group: control group (0) without any treatment; non-pretreatment group (A1, A2), subcutaneous injection of normal saline ; Zn treatment group (B1, B2), subcutaneous injection of ZnCl (Zn25mg per kilogram body weight); Cu treatment of two groups (C1, C2), subcutaneous injection of CuSO (per kg of body weight Cu 12.5mg). After pretreatment for 24 hours, cadmium-metallothionein (Cd-4metallothionein) was subcutaneously injected into the experimental group, causing acute Cd poisoning. Cd1.1mg, A2, B2 and C2 Cd0.4mg per kg body weight. After 24h sacrifice, take the liver, prepare homogenate. After centrifugation, the supernatant was taken and added to a Sephadex G-75 chromatography column. [Results] The main metal element in the liver of the blank control group was Zn and the contents of Cd and Cu were below the limit of detection. Compared with the former, the contents of MT and Cd in the liver of animals in A1 and A2 groups increased with the increase of the dose While the Zn / Cd values in MT of A1 and A2 groups were 20.0 and 10.0, respectively. The Zn / Cd values in MT of B1 and B2 groups were 20.8 and 20.3, respectively, and Cu ions were not detected. MT Cu / Cd values were 80.0 and 36.5, Zn content decreased significantly. [Conclusion] The contents of MT in the liver of animals induced by Zn or Cu were different after exposure to different doses of Cd. The values of Cu / Cd were higher than that of Zn / Cd. Compared with MT bound Cd, Cu could be more easily replaced by MT Of Zn. In addition, non-MT bound Zn in the liver is also an important factor affecting the homeostasis of metal ions bound to MT.