Speciation of arsenic in urine from rats treated with dimethylarsinic acid (DMAV) alone or in combination with dimercaptopropane sulfonate (DMPS) were studied. Methods were developed for the determination of the methylarsenic metabolites, especially trace levels of dimethylarsinous acid (DMAIII) and trimethylarsine oxide (TMAO), in the presence of a large excess of DMAV. Success was achieved by using improved ion-exchange chromatographic separation combined with hydride generation atomic fluorescence detection. Micromolar concentrations of DMAIII were detected in urine of rats fed with a diet supplemented with either 100 μg/g of DMAV or a mixture of 100 μg/g of DMAV and 5600 μg/g of DMPS. No significant difference in the DMAIII concentration was observed between the two groups; however, there was a significant difference in TMAO concentrations. Urine from rats fed with the diet supplemented with DMAV alone contained 73 ± 30 μM TMAO, whereas urine from rats fed with the diet supplemented with both DMAV and DMPS contained only 2.8 ± 1.4 μM TMAO. Solutions containing mixtures of 100 μg/L DMAV or TMAO and 5600 μg/L DMPS did not show reduction of DMAV and TMAO. The significant decrease (p < 0.001) of the TMAO concentration in rats administered with both DMAV and DMPS suggests that DMPS inhibits the biomethylation of arsenic.
研究了单独或与二巯基
丙磺酸盐(
DMPS)一起使用二甲基
砷酸(
DMAV)处理的大鼠尿液中
砷的种类。在
DMAV 大量过量的情况下,开发了测定甲基
砷代谢物,特别是痕量二甲基
砷酸 (
DMAIII) 和
三甲基砷氧化物 (TMAO) 的方法。通过使用改进的离子交换色谱分离技术和
氢化物发生原子荧光检测技术取得了成功。在喂食补充了 100 μg/g
DMAV 或 100 μg/g
DMAV 与 5600 μg/g
DMPS 混合物的大鼠尿液中检测到了微摩尔浓度的
DMAIII。两组大鼠的
DMAIII 浓度无明显差异,但 TMAO 浓度有明显差异。仅以补充
DMAV 的食物喂养的大鼠的尿液中含有 73 ± 30 μM TMAO,而同时以补充
DMAV 和
DMPS 的食物喂养的大鼠的尿液中仅含有 2.8 ± 1.4 μM TMAO。含有 100 μg/L
DMAV 或 TMAO 和 5600 μg/L
DMPS 的混合物溶液并未显示出
DMAV 和 TMAO 的减少。同时使用
DMAV 和
DMPS 的大鼠体内的 TMAO 浓度明显下降(p < 0.001),这表明 DMPS 可抑制砷的
生物甲基化。