代谢
砒霜主要通过吸入或摄入进入人体，较少通过皮肤接触。然后它被分布到全身，如果有必要，它会被还原成亚砷酸盐，然后通过亚砷酸盐甲基转移酶甲基化成单甲基砷（MMA）和二甲砷酸（DMA）。砒霜及其代谢物主要通过尿液排出。已知砒霜可以诱导金属结合蛋白金属硫蛋白，它通过绑定砒霜和其他金属并使其生物活性失效，同时充当抗氧化剂，从而减少砒霜和其他金属的有毒效果。砒霜三氧化物的代谢涉及砷酸盐还原酶将五价砒霜还原为三价砒霜，以及甲基转移酶将三价砒霜甲基化为单甲基砷酸，然后将单甲基砷酸甲基化为二甲砷酸。甲基化反应的主要部位似乎是肝脏。砒霜主要储存在肝脏、肾脏、心脏、肺、头发和指甲中。
消除途径：三价砒霜在人体内大部分被甲基化，并通过尿液排出。
Arsenic is mainly absorbed by inhalation or ingestion, and to a lesser extent by dermal exposure. It is then distributed throughout the body, where it is reduced into arsenite if necessary, then methylated into monomethylarsenic (MMA) and dimethylarsenic acid (DMA) by arsenite methyltransferase. Arsenic and its metabolites are primarily excreted in the urine. Arsenic is known to induce the metal-binding protein metallothionein, which decreases the toxic effects of arsenic and other metals by binding them and making them biologically inactive, as well as acting as an antioxidant. (L20) The metabolism of arsenic trioxide involves reduction of pentavalent arsenic to trivalent arsenic by arsenate reductase and methylation of trivalent arsenic to monomethylarsonic acid and monomethylarsonic acid to dimethylarsinic acid by methyltransferases. The main site of methylation reactions appears to be the liver. Arsenic is stored mainly in liver, kidney, heart, lung, hair and nails.
Route of Elimination: Trivalent arsenic is mostly methylated in humans and excreted in urine.
来源:Toxin and Toxin Target Database (T3DB)
