Methylation and Demethylation of Dimethylarsinic Acid in Rats Following Chronic Oral Exposure

✍ Scribed by Hua Chen; Kaoru Yoshida; Hideki Wanibuchi; Shoji Fukushima; Yoshinori Inoue; Ginji Endo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 474 KB
• Volume: 10
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(199611)10:9<741::aid-aoc551>3.0.co;2-9

✦ Synopsis

Metabolites of dimethylarsinic acid (DMA) were studied in rats chronically exposed to DMA in drinking water. The urine was collected by forced urination at the end of 8, 20 and 30 weeks and the feces at the end of 30 weeks. The samples were analyzed for arsenic species by a combined system of ion chromatography and inductively coupled plasma mass spectrometry (IC-ICP-MS). Increases in arsenite, DMA, trimethylarsine oxide and a still-to-be-identified arsenic compound (which was eluted immediately after monomethylarsonic acid on the chromatogram) were detected in both urine and feces. At the 100 mg 1 -' dose, DMA was the main component in the urine; arsenite was a main component in the feces. The results indicate that, besides undergoing methylation, DMA can be demethylated to inorganic arsenic, and demethylation of DMA may be associated with intestinal bacteria.