Institute of Biology, University of Białystok, Białystok, Poland.
Biol Trace Elem Res. 2012 Jun;147(1-3):189-94. doi: 10.1007/s12011-011-9279-3. Epub 2011 Nov 29.
Bank voles free living in a contaminated environment have been shown to be more sensitive to cadmium (Cd) toxicity than the rodents exposed to Cd under laboratory conditions. The objective of this study was to find out whether benzo(a)pyrene (BaP), a common environmental co-contaminant, increases Cd toxicity through inhibition of metallothionein (MT) synthesis-a low molecular weight protein that is considered to be primary intracellular component of the protective mechanism. For 6 weeks, the female bank voles were provided with diet containing Cd [less than 0.1 μg/g (control) and 60 μg/g dry wt.] and BaP (0, 5, and 10 μg/g dry wt.) alone or in combination. At the end of exposure period, apoptosis and analyses of MT, Cd, and zinc (Zn) in the liver and kidneys were carried out. Dietary BaP 5 μg/g did not affect but BaP 10 μg/g potentiated rather than inhibited induction of hepatic and renal MT by Cd, and diminished Cd-induced apoptosis in both organs. The hepatic and renal Zn followed a pattern similar to that of MT, attaining the highest level in the Cd + BaP 10-μg/g group. These data indicate that dietary BaP attenuates rather than exacerbates Cd toxicity in bank voles, probably by potentiating MT synthesis and increasing Zn concentration in the liver and kidneys.
在受污染环境中自由生活的银行田鼠比在实验室条件下接触 Cd 的啮齿动物对 Cd 毒性更敏感。本研究的目的是确定是否存在常见的环境共污染物苯并(a)芘 (BaP) 通过抑制金属硫蛋白 (MT) 合成——一种被认为是保护机制的主要细胞内成分的低分子量蛋白质，从而增加 Cd 毒性。在 6 周的时间里，雌性银行田鼠被给予含有 Cd[小于 0.1μg/g（对照）和 60μg/g 干重]和 BaP（0、5 和 10μg/g 干重）的饮食，单独或组合使用。暴露期结束时，进行了肝和肾中的细胞凋亡和 MT、Cd 和锌 (Zn) 的分析。膳食 BaP 5μg/g 没有影响，但 BaP 10μg/g 增强而不是抑制了 Cd 诱导的肝和肾 MT 的诱导，并且减少了两种器官中 Cd 诱导的细胞凋亡。肝和肾 Zn 遵循与 MT 相似的模式，在 Cd + BaP 10μg/g 组中达到最高水平。这些数据表明，膳食 BaP 减轻而不是加剧了银行田鼠的 Cd 毒性，可能是通过增强 MT 合成和增加肝和肾中的 Zn 浓度。
