Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi-6205, Bangladesh.
Environ Health. 2011 Jul 8;10:64. doi: 10.1186/1476-069X-10-64.
Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh.
A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed.
Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics.
The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.
慢性砷暴露已被证实会导致肝损伤。然而，血清肝酶活性作为肝功能试验（LFTs）的指标，与砷暴露之间的剂量反应关系尚未得到明确证实。本研究的目的是在孟加拉国砷污染地区，调查砷暴露与主要与 LFTs 相关的血清酶标志物活性之间的剂量反应关系。
本研究共选取了 200 名居住在孟加拉国砷污染地区的居民作为研究对象。采用电感耦合等离子体质谱法（ICP-MS）测量饮用水、头发和指甲中的砷浓度。根据饮用水以及研究对象头发和指甲中的砷浓度，将研究对象分为四组：最低组、低砷组、中砷组和高砷组。然后测定碱性磷酸酶（ALP）、天冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT）的血清肝酶活性。
研究对象头发和指甲中的砷浓度与饮用水中的砷浓度呈正相关。关于与饮用水中砷的暴露反应关系，在调整了不同协变量后，高暴露组的 ALP、AST 和 ALT 活性与低暴露组相比显著升高。对于内暴露标志物（头发和指甲中的砷），ALP、AST 和 ALT 的活性呈现出相似的剂量反应关系，高暴露组与最低暴露组相比差异很小，这很可能是由于暴露指标的时间因素。
本研究表明，饮用水中的砷浓度与研究对象头发和指甲中的砷浓度密切相关。此外，本研究揭示了砷暴露指标与血清肝酶活性之间的新型暴露和剂量反应关系。较高暴露梯度下血清肝酶活性的升高为砷诱导的肝毒性提供了新的见解，这可能有助于砷相关性肝病的早期预后。
