Selenosugar and trimethylselenonium among urinary Se metabolites: dose- and age-related changes
Selenosugar and trimethylselenonium among urinary Se metabolites: dose- and age-related changes
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DOI：
10.1016/j.taap.2004.10.018
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发表时间：
2005-08-01
影响因子：
3.8
通讯作者：
Ogra, Y
中科院分区：
文献类型：
--
作者：
Suzuki, KT;Kurasaki, K;Ogra, Y
硒一旦被人体吸收，主要通过尿液排出，其主要代谢物为1 -甲基硒- n -乙酰基- d -半乳糖（硒糖），在所需的低毒范围内。硒浓度高于2.0 μ g Se/ml水或g日粮时，硒糖出现高原，三甲基硒铵（TMSe）开始升高，提示TMSe可能是硒过量和中毒的生物标志物。本研究通过给大鼠喂食亚硒酸盐，展示两种尿硒代谢物的剂量相关变化，以阐明剂量与尿硒代谢物之间的关系。还研究了代谢物是否与年龄有关，以及n -乙酰- d -半乳糖胺部分的可能外源硫酸软骨素4是否影响尿液代谢物。对36周龄和5周龄雄性Wistar大鼠随意喂食饮用水中的亚硒酸盐，测定其尿液和脏器中硒的浓度及尿中硒代谢产物的形态。在幼龄大鼠中，硒糖始终是尿代谢的主要代谢物，且TMSe随饮水剂量高于2.0 μ g Se/ml而升高。另一方面，在成年大鼠中，尽管大鼠受到的硒毒性更大，但TMSe仅略有增加，这表明TMSe不能作为硒毒性的生物标志物。结果表明，成年大鼠的硒糖的糖部分来源比年轻大鼠更丰富。硫酸软骨素4对两种尿液代谢物的比例没有影响，提示糖源是内源性的，并且随着年龄的增长而增加。(c) 2004 Elsevier Inc.版权所有。
Once selenium (Se) is absorbed by the body, it is excreted mostly into the urine and the major metabolite is 1 beta-methylseleno-N-acetyl-D-galactosamine (selenosugar) within the required to low-toxic range. Selenosugar plateaus with a dose higher than 2.0 mu g Se/ml water or g diet, and trimethylselenonium (TMSe) starts to increase, indicating that TMSe can be a biomarker of excessive and toxic doses of Se. Here, we show dose-related changes in the two urinary Se metabolites to clarify the relationship between the dose and urinary metabolites by feeding selenite to rats. It was also examined whether the metabolites are related to age, and further whether a possible exogenous Source of the N-acetyl-D-galactosamine moiety, chondroitin 4-sulfate, affects the urinary metabolites. Selenite in drinking water was fed ad libitum to male Wistar rats of 36 and 5 weeks of age, and the concentrations of Se ill the urine and organs were determined together with speciation of the urinary Se metabolites. In young rats, selenosugar was always the major urinary metabolite and TMSe increased with a dose higher than 2.0 mu g Se/ml drinking water. On the other hand, in adult rats, TMSe increased only marginally despite that the rats suffered much more greatly from the Se toxicity suggesting that TMSe cannot be a biomarker of Se toxicity. The results suggest that sources of the sugar moiety of selenosugar are more abundant in adult rats than in young rats. Chondroitin 4-sulfate did not affect the ratio of the two urinary metabolites, suggesting that the sugar source is of endogenous origin and that it increases with age. (c) 2004 Elsevier Inc. All rights reserved.