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目的探索小鼠在其早期发育阶段暴露不同浓度亚砷酸钠后,各砷形态在肝和脑组织中的代谢与分布情况。方法母鼠在妊娠和哺乳期以自由饮水方式暴露0、10和30 mg/L iAsⅢ水溶液,仔鼠在哺乳期后继续摄入与母鼠相同浓度的含砷水溶液。分别在仔鼠出生后第0、10、15、21和35天,采用氢化物发生-超低温捕集-原子吸收分光光度法测定肝和脑组织中无机砷(iAs)、一甲基胂(MMA)和二甲基胂(DMA)水平。结果从出生后15 d起,肝组织中iAs含量开始逐步增加;从出生后21 d起,肝组织中MMA含量开始逐步增加;肝组织中DMA含量在出生后10～15 d最低,以后逐步增高。脑组织中iAs含量,在出生后15 d开始升高,在出生后21 d时达最高水平;MMA含量在早期发育阶段的脑组织中没有检测到;DMA含量在出生后10～15 d最低。结论母鼠体内各形态砷化物可通过胎盘屏障进入胎鼠体内,但其基本不能通过乳房屏障进入母鼠乳汁,进而进入仔鼠体内,成熟的血脑屏障对iAs具有一定的阻挡作用,但可允许部分DMA进入脑组织。
Objective To explore the metabolism and distribution of arsenic species in liver and brain tissue of mice exposed to sodium arsenite of different concentrations at their early developmental stages. Methods The pregnant female rats were exposed to 0, 10 and 30 mg / L iAsⅢ aqueous solution freely during pregnancy and lactation. The pups continued to ingest the same concentration of arsenic-containing water as the female rats after lactation. At first, 10th, 15th, 21st and 35th days after birth, the concentrations of inorganic arsenic (iMA) and monomethylarsine (MMA) in liver and brain were measured by hydride generation-cryogenic capture- atomic absorption spectrophotometry ) And dimethylarsine (DMA) levels. Results From the 15th day after birth, the content of iAs in liver tissue began to increase gradually. From the 21st day after birth, the content of MMA in liver tissue began to increase gradually. The content of DMA in liver tissue was the lowest at 10 ~ 15 d after birth and then gradually increased . The content of iAs in brain tissue increased from the 15th day after birth to the highest level at 21 days after birth. The content of MMA was not detected in the early stage of brain tissue. The content of DMA was the lowest at 10 to 15 days after birth. Conclusion All arsenic compounds in the female rats can enter the fetal rat through the placental barrier, but they can not enter the mammary gland through the breast barrier, and then penetrate into the pups. The mature BBB may block the iAs, however, Allow some DMA to enter the brain.