旨在探讨经口暴露的大米砷形态引起的砷毒性以及其生物转化。实验以四个砷含量剂量组（C、S：0.91 mg/kg、M：9.1 mg/kg 和H：30 mg/kg）喂养模拟大米砷形态饲料30 d，通过ICP-MS和HPLC-ICP-MS测定小鼠肠、血、肝脏和肾脏中的砷含量及砷形态（iAsⅢ、iAsⅤ、MMA、DMA和AsB）分布；H&E染色后光学显微镜下观察小鼠肠组织、肝脏和肾脏的组织学变化。结果显示，在C、S、M和H中，血的总砷浓度分别为5.33、8.24、55.75和196.49 μg/kg；肝的总砷浓度分别为14.34、32.70、237.10和708.74 μg/kg；肠中五种砷形态浓度之和分别为27.97、163.12、892.78、3085.325 μg/kg；肾中五种砷形态浓度之和分别10.38、25.79、245.85、1656.14 μg/kg。肠中主要的砷形态为iAsⅢ和DMA，血液中有机砷与无机砷的比值随暴露剂量升高而增加，肝脏和肾脏中主要的砷形态为DMA。与对照组比较，各实验组小鼠肠组织、肝脏和肾脏出现的病理损伤程度随砷暴露剂量的增加而深化，在H组中最明显。本研究表明，短期的大米砷暴露对机体代谢组织无明显损伤，且砷在组织中的累积较少；而高剂量的大米砷暴露将对机体病理结构造成严重损伤；提示长期低剂量的大米砷暴露也可能对机体产生损害。

This work was designed to investigate the toxicity of arsenic caused by oral exposure to rice-simulated arsenic species in four dose groups (C, S: 0.91 mg/kg, M: 9.1 mg/kg and H: 30 mg/kg) and its biotransformation. The arsenic content and arsenic species (iAsⅢ, iAsⅤ, MMAⅤ, DMAⅤ and AsB) distribution in the bowel, blood, liver and kidney of mice were determined by ICP-MS and HPLC-ICP-MS, respectively. The histological changes of bowel tissue, liver and kidney were observed by light microscope after H&E staining. The results showed that in the group of C, S, M and H, the total arsenic concentrations in the blood were 5.33, 8.24, 55.75 and 196.49 μg/kg, respectively; and in the liver were 14.34, 32.70, 237.10 and 708.74 μg/kg, respectively; The sum of the five arsenic species concentrations in the bowel were 27.97, 163.12, 892.78 and 3085.325 μg/kg, respectively; and in the kidney were 10.38, 25.79, 245.85, and 1654.14 μg/kg, respectively. The dominant arsenic species in the bowel were iAsⅢ and DMA. The ratio of organic arsenic to inorganic arsenic in the blood increased with the exposure dose. The main arsenic species in the liver and kidney is DMA. Compared with the control group, the degree of pathological damage in the bowel, liver and kidney of test group was deepened with the increase of arsenic exposure dose. This study shows that the short-term arsenic exposure in rice has no obvious damage to the metabolic tissues of the body, and the accumulation of arsenic in the tissues is less; the high-dose arsenic exposure in rice will cause serious damage to the pathological structure of the body; it suggests that the long-term low-dose arsenic exposure in rice might also cause damage to the body.

广东省自然科学基金项目（2018A030313094，2020A151501457）；东莞市社会发展项目（20185071521641）；高校教育人才“组团式”帮扶专项（4SG19046G）