镉中毒机理研究进展

Progress in the Toxicity Mechanism of Cadmium

镉通过与酶类巯基结合或替代作用,置换出细胞内酶类金属,降低机体抗氧化酶的活性,使机体清除自由基的能力下降,引起氧化损伤;镉可以占据钙离子通道并进入细胞内,使细胞内钙稳态失衡,也可在进入细胞前与细胞表面的孤儿受体上的抗原决定簇胞外锌位点结合,干扰细胞钙代谢;镉能诱导金属硫蛋白的形成,金属硫蛋白参与了镉在机体内的吸收、转运、排泄和蓄积;镉能引起DNA单链断裂,并损害DNA修复系统,导致细胞凋亡。由于镉致机体损伤的机制较为复杂,加之研究者采用的手段差异,影响了人们对其毒性机理的深入探讨。

The cadmium replaces out the intracellular enzymatic metal through combining with the mercapto-or substituting for it,which reduces the activity of the anti-oxidase, decreases the ability to clear the free radical, and causes oxidative damage of the organism. The cadmium can occupy the Ca^(2+) pathway and enter the cell,which makes the intracellular calcium out-of-balance. It also can combine with zinc location of antigen determining cluster on orphan receptor at the surface of cell before entering cell,which interferes cell's calcium metabolism; Cadmium can induce the forming of metal sulfoprotein participating in the absorption, transportation, elimination and accumulation of cadmium in the organism. It can cause DNA single strand to fragment, damage DNA repairing system, which leads to apoptosis. The mechanisms that the cadmium damage the organism are comparatively complicated and the researchers adopt different means,which have affected people's further research on cadmium toxicity mechanisms.