Effects Of Dimethylarsinic Acid Research Articles

Arsenic compounds in the leaves and roots of radish grown in three soils treated by dimethylarsinic acid

The effect of dimethylarsinic acid (DMA) on the growth of radish and the content of As compounds in roots and leaves of the radish were investigated. Radish was grown in pots in three soils (Fluvisols, Chernozems and Luvisols) amended with 20 mg As/kg of soil in form of DMA. Behavior and transformations of DMA in the soils differed depending on the individual soil type. In the first season, plants grew up at Luvisols only. In the second season the plants were able to grow at Luvisols and Chernozems, too. The roots and leaves of radish from Luvisols had DMA as the dominant arsenic compound present (~ 90% in the extract) in the first season. In the roots of the subsequently growing radish DMA accounted for 20% and arsenite for most of the total arsenic in the extract. In the leaves of the second-crop of radish DMA remained the dominant arsenic compound (~ 60% in the extract) with arsenate and arsenite for the remaining 40%. Roots and leaves of radish grown in Chernozems and Luvisols had a similar pattern of arsenic compounds. Soil properties significantly affected transformation of As species in the soils. At Fluvisols was the lowest As immobilization and about 98% was found as DMA after two years of experiments in the other two soils was higher As immobilization and DMA was recovered to inorganic As (V) – 31% in Luvisols and 78% in Chernozems.

Dimethylarsinic acid causes inhibition of microtubule assembly and inhibition of calcium‐sensitive disassembly of microtubules via interaction with glutathione

AbstractThe effects of dimethylarsinic acid (DMAA) on microtubule assembly in vitro were investigated in terms of the role of glutathione (GSH). Increase in turbidity due to assembly of brain tubulins was monitored in the presence or absence of DMAA. DMAA at concentrations up to 10 mM did not cause inhibition of the increased turbidity. GSH at concentrations over 10 mM enhanced the increase in turbidity. By contrast, the increased turbidity was inhibited markedly when DMAA and GSH were combined in the ratio of 5:1. Moreover, the combination similarly inhibited calcium‐induced disassembly of microtubules with a potency equivalent to that of 10 µM taxol. These results suggest that DMAA inhibited not only microtubule assembly, but also calcium‐sensitive disassembly of microtubules, via interaction with GSH. Copyright © 2002 John Wiley & Sons, Ltd.

The role of orally administered dimethylarsinic acid, a main metabolite of inorganic arsenics, in the promotion and progression of UVB-induced skin tumorigenesis in hairless mice

The effect of dimethylarsinic acid (DMA) on skin tumorigenesis by UVB irradiation was examined. Hairless mice (Hos: HR-1) irradiated with UVB at a dose of 2 kJ/m 2 twice weekly, were fed with drinking water containing 1000 ppm DMA, a main metabolite of inorganic arsenics, produced more skin tumors than DMA-untreated mice. Histopathological examination revealed that the mouse malignant tumors with severe atypism appeared only in the treatment group of UVB plus 1000 ppm DMA. These positive results point out the importance of dimethylated metabolites of inorganic arsenic in the process of skin carcinogenesis.