亚砷酸钠和砷酸钠染毒大鼠尿液砷形态分析

目的 分析亚砷酸钠和砷酸钠染毒大鼠尿液中砷形态代谢产物水平,寻找不同价态砷代谢的差异,为进一步探讨砷代谢产物与砷毒性作用机制间的关系提供基础数据.方法 Wistar大鼠70只,体质量80～120 g,按体质量随机分为7组,即对照组、亚砷酸钠高、中、低剂量组和砷酸钠高、中、低剂量组,每组10只.各组大鼠染毒1个月后,收集12 h尿液,采用高效液相色谱-氢化物发生原子荧光光谱法(HPLC-HGAFS)测定尿液中砷形态代谢产物水平,并通过二甲基砷酸(DMA)加标回收率测定来评价结果准确度.结果 亚砷酸钠中剂量组尿液中各种代谢物3价无机砷(iAs~(3+))、5价无机砷(iAs~(5+))、DMA]水平(121.66±1.26)、(10.26±2.68)、(204.91±0.56)μg/L]高于高剂量组(113.20±0.75)、(5.16±1.32)、(147.70±0.77)μg/L,P均<0.05]和低剂量组(79.35±2.12)、(5.13±2.25)、(56.35±1.23)μg/L,P均<0.05];砷酸钠中剂量组尿液中iAs~(3+)和DMA水平(315.81±1.69)、(245.12±1.18)μg/L]高于高剂量组(85.03±0.56)、(110.34±1.04)μg/L,P均<0.05]和低剂量组(22.97±2.67)、(15.75±2.15)μg/L,P均<0.05].亚砷酸钠高、低剂量组尿液中iAs~(3+)和DMA水平高于砷酸钠组(P均<0.05);而亚砷酸钠中剂量组尿液中iAs~(3+)和DMA水平低于砷酸钠组(P均<0.05).亚砷酸钠高、中、低剂量组DMA的平均加标回收率为94.80%～102.70%,砷酸钠高、中、低剂量组DMA的平均加标回收率为95.33%～108.40%.结论 染砷价态及外暴露剂量不同,大鼠体内砷代谢物的形态和水平就不同;不同价态无机砷在大鼠体内的代谢径路不完全相同.

Analysis on the arsenic speciation in urine of rats treated with sodium arsenite and sodium arsenate

Objective To analyze the levels and speciation of arsenic metabolites in urine of rats treated with sodium arsenite and sodium arsenate in order to investigate the different aspects of metabolism between sodium arsenite and sodium arsenate,thus to understand further the basic data about relationship between it's metabolism and mechanism of toxicity. Methods Seventy Wistar rats,weighting 80-120 g,were divided into 7 groups of 10 each,such as normal control group,high,middle and low sodium arsenite group and high,middle and low sodium arsenate group. After the animals were fed for one month,the urine was collected by metabolic cage in 12 hours. Applying the high efficiency liquid chromatography and hydride genesis atomic fluorescence spectroscopy (HPLC-HGAFS),the levels and speciation of arsenic metabolites were determined in urine of rats. Meanwhile,the recovery rate of dimethyl arsinic acid(DMA) would be determined to estimate the degree of accuracy of results. Results The levels of iAs~(3+),iAs~(5+) and DMA in middle sodium arsenite group(121.66±1.26),(10.26±2.68),(200.91±0.56) μg/L]were higher than the high sodium arsenite group(113.20±0.75),(5.16±1.32),(147.70±μ0.77)μg/L,all P < 0.05]and low sodium arsenite group(79.35±2.12),(5.13±2.25),(56.35±1.23)μg/L,all P < 0.05]. The levels of iAs~(3+) and DMA in middle sodium arsenate group(315.81±1.69),(245.12±1.18)μg/L]were higher than the high sodium arsenate group(85.03±0.56),(110.34±1.04)μg/L,all P< 0.05]and low sodium arsenate group(22.97±2.67),(15.75±2.15)μg/L,all P < 0.05]. Compared with sodium arsenate group,the levels of iAs~(3+) and DMA in high and low sodium arsenite group were higher(all P < 0.05) ; and the levels of iAs~(3+) and DMA in middle sodium arsenite group were lower(all P < 0.05). Meanwhile,the average urinary recovery rate of DMA of rats in different sodium arsenite group were 94.80%-102.70%,and the average urinary recovery rate of DMA of rats in different sodium arsenate group were 95.33%-108.40%. Conclusion The speciation and levels of arsenic are influenced by the external exposure dose,and some distinction appeared in the metabolism and metabolic path between sodium arsenite and sodium arsenate in urine in vivo.