Arsenic Speciation in the Blood of Arsenite-Treated F344 Rats

详细信息    查看全文

• 作者：Baowei Chen ; Xiufen Lu ; Shengwen Shen ; Lora L. Arnold ; Samuel M. Cohen ; X. Chris Le
• 刊名：Chemical Research in Toxicology
• 出版年：2013
• 出版时间：June 17, 2013
• 年：2013
• 卷：26
• 期：6
• 页码：952-962
• 全文大小：406K
• 年卷期：v.26,no.6(June 17, 2013)
• ISSN：1520-5010

文摘

Arsenic speciation in blood can improve understanding of the metabolism and toxicity of arsenic. In this study, arsenic species in the plasma and red blood cells (RBCs) of arsenite-treated female F344 rats were characterized using anion exchange and size exclusion chromatography separation with inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization tandem mass spectrometry (ESI MS/MS) detection. Arsenite (iAs^III), arsenate (iAs^V), monomethylarsonic acid (MMA^V), dimethylarsinic acid (DMA^V), trimethylarsine oxide (TMAO^V), monomethylmonothioarsonic acid (MMMTA^V), and dimethylmonothioarsinic acid (DMMTA^V) were detected in the plasma, with DMA^V being the predominant metabolite. Upon oxidative pretreatment with 5% hydrogen peroxide (H₂O₂), plasma proteins released bound arsenic in the form of DMA^V as the major species and MMA^V as the minor species. The ratio of protein-bound arsenic to total arsenic decreased with increasing dosage of iAs^III administered to the rats, suggesting a possible saturation of the binding capacity of the plasma proteins. The proportion of the protein-bound arsenic in the plasma varied among rats. In the H₂O₂-treated lysates of red blood cells of rats, DMA^V was consistently found as the predominant arsenic species, probably reflecting the preferential binding of dimethylarsinous acid (DMA^III) to rat hemoglobin. iAs^V, MMA^V, and trimethylarsine oxide (TMAO^V) were also detected in the hydrogen peroxide-treated lysates of red blood cells. Importantly, DMMTA^V and MMMTA^V have not been reported in rat blood, and the present finding of DMMTA^V and MMMTA^V in the rat plasma is toxicologically relevant because these pentavalent thioarsenicals are more toxic than their counterparts DMA^V and MMA^V. Identifying novel thiolated arsenicals and determining protein-bound arsenicals in the blood provide useful insights into the metabolism and toxicity of arsenic in animals.