Enteric bacteria may play a role in mammalian arsenic metabolism

✍ Scribed by Koichi Kuroda; Kaoru Yoshida; Akira Yasukawa; Hideki Wanibuchi; Shoji Fukushima; Ginji Endo

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 80 KB
• Volume: 15
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.193

✦ Synopsis

Abstract

The cecal content of rats administered dimethylarsinic acid for 6 months via drinking water was cultured in GAM medium with 10 mg l^−1^ of dimethylarsinic acid. Arsenic compounds in the culture were analyzed by ion chromatography with inductively coupled plasma mass spectrometry (IC–ICP‐MS). Dimethylarsinic acid was metabolized. Two bacterial Escherichia coli strains, A3‐4 and A3‐6, were isolated from the culture. These strains metabolized dimethylarsinic acid and yielded two unidentified arsenic compounds, M‐2 and M‐3. A3‐6 methylated dimethylarsinic acid to trimethylarsine oxide. Both strains metabolized trimethylarsine oxide and yielded an unidentified arsenic compound, M‐1. These unknown arsenic compounds were the same compounds as detected in the urine and the feces of rats administered dimethylarsinic acid. The strains reduced arsenate to arsenite efficiently. Cysteine was required for metabolism of dimethylarsinic acid by these bacteria, but glutathione was not required. These results strongly suggested that the intestinal bacteria have a different arsenic metabolism from that in mammals and that they may play a possible role in mammalian arsenic metabolism. Copyright © 2001 John Wiley & Sons, Ltd.