Less information is available on the metabolism of organic arsenicals compared to inorganic arsenic in mammals. In the present study, we investigated tissue distribution, metabolism and excretion in rats of organoarsenicals, dimethylarsinic acid (DMA
V), arsenobetaine (AB), arsenocholine (AC) and trimethylarsine oxide
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Less information is available on the metabolism of organic arsenicals compared to inorganic arsenic in mammals. In the present study, we investigated tissue distribution, metabolism and excretion in rats of organoarsenicals, dimethylarsinic acid (DMA
V), arsenobetaine (AB), arsenocholine (AC) and trimethylarsine oxide (TMAO
V). Among these animals, arsenic concentrations in red blood cells (RBCs) and spleen increased remarkably only in the DMA
V group. Hepatic arsenic concentration increased significantly only in the AC group. Approximately 17%, 72% and 60% of the dose was excreted in urine in two days in the DMA
V, AB and AC groups, respectively; virtually the entire dose was excreted in urine in one day in the TMAO
V group. On the other hand, approximately 18%, 0.2%, 0.5% and 0.1% of the dose was excreted in feces in two days in the DMA
V, AB, AC and TMAO
V groups, respectively. A large amount of arsenic was accumulated in RBCs in the form of protein-bound dimethylarsinous acid (DMA
III), and dimethylmonothioarsinic acid (DMMTA
V), a reportedly toxic thio-arsenical, was found in urine and fecal extract in the DMA
V group. These results suggest that intake of DMA
V is a potential health hazard, given that the metabolites of DMA
V, such as DMA
III and DMMTA
V, are known to be highly toxic.
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