Effect of High Sensitive Factor on Distribution of Cadmium Using Iron-deficient Metallothionein-l/II Null Mice

我们研究了金属硫蛋白和膳食铁对妊娠期暴露于镉（50 ppm）下镉分布的影响，使用缺铁金属硫蛋白1 /II缺失的妊娠小鼠。在镉暴露野生型小鼠中，与正常铁饮食组相比，低铁饮食组母肝、母肾和胎肝中的镉浓度显著升高。相反，在镉暴露的金属硫蛋白1 /II缺失小鼠中，低铁饮食组母体肝脏和肾脏中的镉浓度显著高于正常铁饮食组。然而，在镉暴露的金属硫蛋白1 /II缺失小鼠胎儿肝脏中，低铁饲粮组与正常铁饲粮组镉浓度无显著差异。低铁饮食组和正常铁饮食组，金属硫蛋白- 1 /II缺失小鼠母鼠肝脏和肾脏中镉浓度均显著低于野生型小鼠，而金属硫蛋白- 1 /II缺失小鼠胎鼠肝脏中镉浓度显著高于野生型小鼠。另一方面，四组（金属硫蛋白- 1 /II缺失小鼠低铁饮食组、野生型小鼠低铁饮食组、金属硫蛋白- 1 /II缺失小鼠正常铁饮食组和野生型小鼠正常铁饮食组）胎盘中镉的浓度无显著差异。上述结果提示，金属硫蛋白和铁在抑制胎儿肝脏镉积累中起重要作用。在妊娠期镉暴露中，金属硫蛋白对小鼠胎儿镉积累的影响强于铁。

We examined the effects of metallothionein and dietary iron on the distribution of cadmium in exposure to cadmium (50 ppm) during gestation using the iron-deficient metallothionein-l/II null pregnant mice. In the cadmium-exposed wild-type mice, cadmium concentrations in the maternal liver, maternal kidney and fetal liver of low iron diet group significantly increased compared with those of normal iron diet group. In contrast, in the cadmium-exposed metallothionein-l/II null mice, cadmium concentrations in the maternal liver and kidney of low iron diet group were significantly higher than those of normal iron diet group. However, in the fetal liver of cadmium-exposed metallothionein-l/II null mice, cadmium concentration was not different between low iron diet group and normal iron diet group. Furthermore, in the both low iron diet group and normal iron diet group, cadmium concentrations in the maternal liver and kidney of metallothionein-l/II null mice exposed to cadmium markedly decreased compared with those of wild-type mice whereas cadmium concentration in the fetal liver of metallothionein-l/II null mice was significantly higher than that of wild-type mice. On the other hand, cadmium concentration in the placenta was not different between four groups, which are low iron diet group in metallothionein-l/II null mice, low iron diet group in wild-type mice, normal iron diet group in metallothionein-l/II null mice and normal iron diet group in wild-type mice. These results suggested that metallothionein and dietary iron plays an important role in the inhibition of cadmium accumulation in the fetal liver. In the gestational exposure to cadmium, effect of metallothionein on the cadmium accumulation in the fetus of mice was stronger than that of dietary iron.