[Dimethylarsinous acid-promoted skin tumorigenesis through the induction of oxidative stress in mice].

Objective: To investigated the relationship between skin-tumor promotion and oxidative stress caused by dimethylated arsenic in mice.

Methods: The experimental animal model was used to examine the effect of dimethylated arsenic, a metabolite of DMA(V), dimethylarsinous acid (DMA(III)) in skin tumorigenesis in mice. The 8-oxo-2'-deoxyguanosine (8-oxodG) analysis of epidermis was based on the method of HPLC.

Results: When mice were topically treated with trivalent dimethylated arsenic (DMA(III)), a further reductive metabolite of DMA(V), not only an increase in skin tumors but also an elevation of 8-oxodG in epidermis were observed.

Conclusion: These results suggest that tumor promotion due to DMA(V) administration is mediated by DMA(III) through the induction of oxidative stress.