Animal Species Difference in the Uptake of Dimethylarsinous Acid (DMAIII) by Red Blood Cells

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• 作者：Yamato Shiobara ; Yasumitsu Ogra ; and Kazuo T. Suzuki
• 刊名：Chemical Research in Toxicology
• 出版年：2001
• 出版时间：October 2001
• 年：2001
• 卷：14
• 期：10
• 页码：1446 - 1452
• 全文大小：101K
• 年卷期：v.14,no.10(October 2001)
• ISSN：1520-5010

文摘

The animal species difference in the metabolism of arsenic was studied from the viewpointof the mechanism underlying its distribution in the form of dimethylated arsenic in red bloodcells (RBCs). Dimethylarsinic (DMA^V) and dimethylarsinous (DMA^III) acids were incubatedwith rat, hamster, mouse, and human RBCs, and the uptake rates and chemical forms of arsenicwere determined. Although DMA^V was practically not or taken up slowly by RBCs of all thepresent animal species, DMA^III was taken efficiently in the order of rat > hamster > human,RBCs of mice taking it up less efficiently and with a different pattern from the former threeanimals. Further, although DMA^III taken up by rat RBCs was retained, that by hamster oneswas effluxed in the form of DMA^V. The uptake of DMA^III and efflux of DMA^V took place muchmore slowly in human RBCs than rat and hamster ones. The uptake of DMA^III by RBCs wasinhibited on the oxidation of glutathione with diamide. Incubation of DMA^III, but not of DMA^V,with a hemolysate produced a high molecular weight complex, which increases in the presenceof glutathione, suggesting that DMA^III taken up by RBCs is retained through the formation ofa complex with protein(s) specific to animal species, and effluxed from RBCs after being oxidizedto DMA^V. These results indicate that DMA is taken up by RBCs in the form of DMA^III, andthat the uptake and efflux rates are dependent on the animal species, the effluxed arsenicbeing DMA^V. The present results suggest that the uptake of DMA by RBCs is an additionalcontributing factor to the animal species difference in the metabolism of arsenic in addition tothe reduction and methylation capacity in the liver.