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- Chen, Liang, et al.
(författare)
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Critical exposure level of cadmium for elevated urinary metallothionein--an occupational population study in China.
- 2006
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Ingår i: Toxicology and applied pharmacology. - : Elsevier BV. - 0041-008X. ; 215:1, s. 93-9
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Tidskriftsartikel (refereegranskat)abstract
- Cadmium is a well-known nephrotoxic agent with extremely long biological half-time of 15-30 years in humans. To prevent nephrotoxicity induced by cadmium, it is necessary to identify specific and sensitive biomarkers of cadmium exposure and renal damage, and to define critical exposure levels related to minimal nephrotoxicity in humans. In this study, urinary cadmium (UCd) and blood cadmium (BCd) were used as cadmium exposure indicators, urinary beta(2)-microglobulin (UB2M), N-acetyl-beta-D-glucosaminidase (UNAG) and albumin (UALB) were applied as the effect biomarkers of tubular and glomerular dysfunction. The relationship between urinary metallothionein (UMT) and cadmium exposure biomarkers as well as effect biomarkers was examined. Significant correlations were found between the UMT and BCd, and UCd. At the same time, UB2M, UALB and UNAG showed positive correlation with UMT as well. According to this result, cadmium-exposed individuals with renal dysfunction excreted more metallothionein than those without. Dose-response relationships between UCd and urinary indicators of renal dysfunction were studied. The critical concentration of UCd was quantitatively estimated by the benchmark dose (BMD) method. The lower confidence limit of the BMD-10 (BMDL) of UCd (3.1 microg/g Cr) related to increased excretion of urinary metallothionein was slightly higher than that for UNAG (2.7 microg/g Cr), but lower than those of UB2M (3.4 microg/g Cr) and UALB (4.2 microg/g Cr). The results demonstrate that UMT may be used as a sensitive biomarker of renal tubular dysfunction in cadmium-exposed populations.
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| 2. |
- Chen, Liang, et al.
(författare)
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Plasma metallothionein antibody and cadmium-induced renal dysfunction in an occupational population in China.
- 2006
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Ingår i: Toxicological sciences : an official journal of the Society of Toxicology. - : Oxford University Press (OUP). - 1096-6080. ; 91:1, s. 104-12
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Tidskriftsartikel (refereegranskat)abstract
- It has been reported that anti-metallothionein (a metallothionein antibody) is present in the circulation of healthy subjects and in patients suffering from atopic dermatitis. The aim of this study was to investigate whether cadmium-induced renal dysfunction is related to the presence of the plasma metallothionein antibody (MT-Ab) in workers exposed to cadmium (Cd) occupationally. Plasma metallothionein antibody was determined by enzyme linked immunosorbent assay (ELISA) techniques, and both exposure assessment and risk assessment were conducted in cadmium-exposed workers in China. We demonstrate that there is a significantly increased prevalence of renal dysfunction with respect to the level of urinary cadmium in a dose-dependent manner. We found no significant correlations between the levels of MT-Ab and the external or internal exposure doses of cadmium (p > 0.05), but the levels of MT-Ab did correlate positively with two biomarkers of renal dysfunction-urinary beta2-microglobulin (UB2M; r = 0.218, p < 0.05) and N-acetyl-beta-D-glucosaminidase (UNAG; r = 0.302, p < 0.001)-in the cadmium-exposed workers. Workers who have high levels of MT-Ab display cadmium-induced tubular nephrotoxicity more frequently than those possessing low levels of MT-Ab; odds ratio (OR) 4.2; 95% confidence intervals 1.2-14.5 (p < 0.05). This study suggests that subjects that have higher MT-Ab levels more readily develop cadmium-induced renal dysfunction. Thus, the levels of plasma MT-Ab can be used as a biomarker of susceptibility to renal dysfunction in occupational cadmium exposure.
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