A review of arsenicals in biology

The most toxic form of arsenic is arsine gas. Arsenite is also highly toxic and arsenate is moderately toxic. Arsine gas will lyse red blood cells, arsenite inactivates particular enzymes and arsenate uncouples oxidative phosphorylation. Arsenic does not appear to be a significant mutagen. Epidemiological studies have implicated arsenic as a cause of lung cancer and skin cancer, but arsenic generally does not induce cancer in laboratory animals. Arsenic may bioaccumulate in some plants and marine organisms. Bacteria can be resistant to arsenic by preventing arsenate from entering the cell (chromosomal resistance) or pumping arsenic out of the cell (plasmid resistance). Many different organisms, including mammals, have the ability to methylate inorganic arsenic. Biomethylation seems to be a mechanism of arsenic detoxification.

Key words:

• Arsenic
• resistance
• poisoning
• biomethylation
• mutagenicity
• carcinogenicity