Chmielnicka J, Sowa B
Department of Toxicological Chemistry, Medical University of Lódź, Lódź, 90-151, Poland.
Ecotoxicol Environ Saf. 1996 Dec;35(3):277-81. doi: 10.1006/eesa.1996.0111.
Cadmium administered to rats per os is accumulated in the duodenal mucosa in the form of metallothionein (MT). Therefore, this toxic metal can influence the efficiency of essential metal absorption, especially their concentration in the maternal organism, which plays an essential role during fetal development. The aim of this study is to elucidate the mechanism of the origin of Zn, Cu, and Fe deficiency in fetal rat livers after maternal exposure to cadmium in drinking water and to investigate the roles of MT and ceruloplasmin (Cp) in this phenomenon. Cadmium was given to pregnant dams exposed for 0-20 days of gestation in drinking water at concentrations of 6. 25-100 microg Cd/ml. After cessation of exposure, at the lowest dose, a decrease in Cu and Fe concentrations in the duodenal mucosa was found. Simultaneously, diminution in concentration of two cited metals and Cp activity in serum of dam blood was noted. The lowest dose of cadmium developed a drop tendency in microsomal fetal liver iron. Significant correlations were observed between fetal liver Cu contents and Cp activity in serum of dams and Cu concentrations in serum of dams. Diminished Cp activity in serum of dams is related to reduced availability of Cu and Fe in fetuses. In conclusion, it is suggested that the mechanism of Cu and Fe deficit content in fetuses is based on the diminution of absorption of these metals by dam intestines exposed to cadmium on the reduction of metal concentrations in blood serum and, in consequence, their decreasing availability in fetuses.
经口给予大鼠的镉以金属硫蛋白(MT)的形式蓄积在十二指肠黏膜中。因此,这种有毒金属会影响必需金属的吸收效率,尤其是它们在母体中的浓度,而母体在胎儿发育过程中起着至关重要的作用。本研究的目的是阐明母体在饮用水中接触镉后胎鼠肝脏中锌、铜和铁缺乏的起源机制,并研究MT和铜蓝蛋白(Cp)在这一现象中的作用。在妊娠0至20天期间,给怀孕的母鼠饮用含镉浓度为6.25 - 100微克/毫升的水。停止接触后,在最低剂量下,发现十二指肠黏膜中的铜和铁浓度降低。同时,母鼠血液血清中上述两种金属的浓度降低以及Cp活性降低。最低剂量的镉使胎鼠肝脏微粒体铁呈现下降趋势。观察到胎鼠肝脏铜含量与母鼠血清中Cp活性以及母鼠血清中铜浓度之间存在显著相关性。母鼠血清中Cp活性降低与胎儿体内铜和铁的可利用性降低有关。总之,提示胎儿体内铜和铁含量不足的机制是基于接触镉的母鼠肠道对这些金属的吸收减少,血清中金属浓度降低,进而胎儿体内金属的可利用性降低。