Akesson A, Stål P, Vahter M
Institute of Environmental Medicine, Division of Metals and Health, Karolinska Institutet, Stockholm, Sweden.
Environ Health Perspect. 2000 Apr;108(4):289-91. doi: 10.1289/ehp.108-1638026.
The intestinal absorption of the nephrotoxic environmental pollutant cadmium increases markedly when iron stores are depleted. This may be mediated by an up regulation of the recently identified mucosal transporter DMT1 (Nramp2 or DCT1) for divalent cations. We tested whether the highly increased iron absorption in hereditary hemochromatosis (HH) was accompanied by an enhanced absorption of cadmium and lead. Cadmium and lead in blood and iron status markers were determined in 21 nonsmoking subjects with HH genetically tested for the HFE mutations and in 21 nonsmoking controls matched for age and sex. In subjects with HH on maintenance phlebotomy treatment, blood concentrations of cadmium, but not lead, were significantly higher than in paired controls. There was a strong age-independent positive association between blood cadmium and the number of years of phlebotomy treatment. Blood lead showed a similar but less pronounced consequence of treatment. All HH subjects with lower blood cadmium than the corresponding controls had either no mutation in the HFE gene, were not phlebotomized, or were phlebotomized for only a limited time. Our findings indicate that the treatment rather than the disease increased the cadmium uptake in homozygous HH. Further studies are needed to confirm whether the disease decreased cadmium absorption and whether the absorption was dependent on the genotype.
当铁储备耗尽时，肾毒性环境污染物镉的肠道吸收会显著增加。这可能是由最近发现的二价阳离子黏膜转运体DMT1（Nramp2或DCT1）的上调介导的。我们测试了遗传性血色素沉着症（HH）中高度增加的铁吸收是否伴随着镉和铅吸收的增强。对21名经基因检测有HFE突变的非吸烟HH患者以及21名年龄和性别匹配的非吸烟对照者测定了血液中的镉、铅以及铁状态标志物。在接受维持性放血治疗的HH患者中，血液镉浓度显著高于配对对照者，但铅浓度无显著差异。血液镉与放血治疗年限之间存在强烈的、与年龄无关的正相关。血液铅也显示出类似但不太明显的治疗结果。所有血液镉浓度低于相应对照者的HH患者，要么HFE基因无突变，要么未接受放血治疗，要么仅接受了有限时间的放血治疗。我们的研究结果表明，在纯合子HH中，是治疗而非疾病增加了镉的摄取。需要进一步研究来证实疾病是否降低了镉的吸收以及吸收是否依赖于基因型。
