小鼠体内砷甜菜碱向无机砷的生物降解

Biodegradation of Arsenobetaine into Inorganic Arsenic in Mice

砷在高浓度下对生物体具有极高的毒性,然而,关于低毒性的砷甜菜碱(AsB)在哺乳动物体内生物转化的研究有限。AsB对人体是否造成潜在健康影响,最近引起了广泛的关注。因此,本研究评估了AsB和无机砷形态在小鼠体内的差异吸收、生物转化和生物积累。为此,C57BL/6J小鼠以1000μg·kg^(-1)剂量口服AsB和无机砷(iAs)14 d。随后,收集组织/器官样本以及尿液和粪便样本进行分析。结果表明,AsB的口服吸收率最高。此外,我们观察到AsB经口服后向砷酸盐(As(Ⅴ))发生显著生物转化,相较于亚砷酸盐(As(Ⅲ))或As(Ⅴ)处理的小鼠,AsB处理小鼠的肝脏、肺和脾脏中砷积累水平更高。在短期接触AsB后,iAs在肺和脾脏中表现出较高的积累水平。总的来说,这些发现提供了强有力的证据,证明在哺乳动物中,AsB经历了向iAs的生物转化,同时表明哺乳动物长期摄入AsB存在潜在的健康风险。

At high concentrations,As is extremely toxic to living organisms,and recently,the biotransformation of As species,including arsenobetaine(AsB),has attracted considerable attention owing to their health effects following their ingestion.However,studies on the biotransformation of AsB in mammals are limited.Therefore,in this study,our objective was to evaluate the differential absorption,biotransformation,and bioaccumulation of As species in mice.To this end,C57BL/6J mice were orally administered AsB and inorganic As(iAs)for 14 d at a dose of 1000μg·kg^(-1).Thereafter,tissue/organ samples as well as urine and fecal samples were collected for analysis.The results obtained showed that AsB had the highest oral absorption rate.Additionally,we observed a significant biotransformation of AsB to arsenate(As(Ⅴ))following its oral administration,and the liver,lungs,and spleen of AsB-treated mice showed higher As accumulation levels than those of arsenite(As(Ⅲ))-or As(Ⅴ)-treated mice.Further,after the short-term exposure to AsB,iAs showed a relatively high accumulation level in the lungs and spleen.Overall,these findings provided strong evidence that in mammals,organic AsB undergoes biotransformation to iAs,indicating the potential health risk associated with long-term AsB intake in mammals.