Objective To observe the metabolism and distribution of arsenic in liver and brain of offspring rata by exposure to arsenic of pregnant rats or lactation dams and weaned pups,and explore if arsenic could penetrate the placental barrier,lactation barrier and blood brain barrier. Methods The Wistar female rots were randomly divided into four groups according to body weights,12 in each group,and were fed with drinking water that contained arsenic(NaAsO_2) 0,10,50,100 mg/L beginning from the gestafional day 6 until pups 42 days old. Pups were separately sacrificed on postnatal day(PND) 0,15,28,42. Arsenic in liver and brain of offspring rots and in breast milk was examined by atomic absorption speetrophotometer with an arsenic speeiation pretreatment system. Results Concentration of iAs,MMA,DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[0,0,0,(7.3±6.6),0,(44.2±27.4)ng/g]on PND 0,42[iAs: (120.0±46.0),(195.5±125.3),(216.5±278.4),(176.6±151.8) ng/g; M MA: (47.2±18.1),(199.6±389.1),(47.4±55.2),(82.7±79.2) ng/g; DMA: (984.3±377.4),(2222.1±1433.2),(998.1±368.3),(1781.3±715.7)ng/g,all P < 0.05]. Concentration of DMA of brain in 50,100 mg/L groups were higher than that of 0 mg/L group[(13.9±18.1),(50.6±98.3)ng/g]on PND 15,28 [(270.3±73.1),(323.9±72.7),(758.7±245.9),(1020.6±383.6) ng/g,all P < 0.05]. Concentration of iAs,DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group [(1.4±3.5),(49.7± 47.1),0,(100.4±30.2)ng/g]on PND 28,42 [iAs: (37.5±28.1),(268.8±246.4),(307.2±339.9),(15.4±9.4),(479.1±161.1),(408.4±51.9)ng/g;DMA: (594.5±148.8),(3181.9±519.0),(4834.2±2568.4),(1061.8± 85.2),(3697.1±553.7),(4120.0±732.8) ng/g,all P < 0.05]. Concentration of DMA of liver in 10,50,100 mg/L groups were higher than that of 0 mg/L group[(13.2±20.5)ng/g]on PND 15[(182.0±60,2),(637.6±90.0),(1458.7±196.3)ng/g,all P < 0.05]. Concentration of arsenicals of liver and brain showed a dose-dependent increase. The concentrations of DMA of breast milk in 50,100 mg/L groups were also higher than that of 0 mg/L group[(9.8±13.4),0 ng/g]on PND 0,15 [(182.3±85.9),(372.2±203.9),(124.2±33.1),(244.4±196.5)ng/g,all P < 0.05]. In the analysis of the change of arsenic on different postnatal day,we found the concentration of iAs,MMA,DMA,TMA in liver and brain of pups all decreased on postnatal day 15,and was lower than that on PND 0,28 and 42. Conclusions The distribution of arsenic and methyl-metabolism in liver and brain of pups is related with arsenic exposure dose. Arsenic can penetrate the placenta and blood brain barrier easily and lactation can hinder arsenic intake in some extent.%目的 观察孕期和哺乳期砷暴露对子代大鼠脑、肝组织砷代谢与分布的影响,探讨砷在大鼠体内通过胎盘屏障、乳汁屏障以及血脑屏障的情况.方法 将Wistar雌性大鼠按体质量随机分为4组,每组12只,于妊娠第6天开始分别饮用含亚砷酸钠(NaAsO_2)0、10、50、100 ms/L的蒸馏水.于子代大鼠出生第0、15、28、42天,用氢化物发生-冷原子捕获-原子吸收分光光度法测定其体内肝、脑组织及母乳含砷量.结果 子代大鼠出生第0、42天,50、100 mg/L组仔鼠脑组织中iAs水平[(120.0±46.0)、(195.5±125.3),(216.5±278.4)、(176.6±151.8)ng/g]、MMA[(47.2±18.1)、(199.6±389.1),(47.4±55.2)、(82.7±79.2)ng/g]、DMA[(984.3±377.4)、(2222.1±1433.2),(998.1±368.3)、(1781.3±715.7)ng/g]均高于0 mg/L组[0、0、0,(7.3±6.6)、0、(44.2±27.4)ng/g,P均<0.05],在出生第15、28天,50、100mg/L组仔鼠脑组织中DMA水平[(270.3±73.1)、(323.9±72.7),(758.7±245.9)、(1020.6±383.6)ng/g]高于0 mg/L组[(13.9±18.1),(50.6±98.3)ns/g,P均<0.05).出生后第28、42天,10、50、100 mg/L组仔鼠肝组织中iAs[(37.5±28.1)、(268.8±246.4)、(307.2±339.9),(15.4±9.4)、(479.1±161.1)、(408.4±51.9)ng/g]、DMA水平[(594.5±148.8)、(3181.9±519.0)、(4834.2±2568.4),(1061.8±85.2)、(3697.1±553.7)、(4120.0±732.8)ng/g]明显高于0 mg/L组[(1.4±3.5)、(49.7±47.1),0、(100.4±30.2)ng/g,P均<0.05],而在出生第15天,10、50、100 mg/L组仔鼠肝组织DMA[(182.0±60.2)、(637.6±90.0)、(1458.7±196.3)ng/g]高于0 mg/L组[(13.2±20.5)ng/g,P均<0.05].脑、肝中各种形态砷化物均随饮水砷暴露浓度的增高而增加.第0、15天50、100 mg/L组母鼠乳汁中的DMA[(182.3±85.9)、(372.2±203.9),(124.2±33.1)、(244.4±196.5)ng/g]也明显高于0 mg/L组[(9.8±13.4),0ng/g,P均<0.05].且各组仔鼠脑、肝组织中各种形态砷化物均在出生后第15天出现一个降低的趋势,在第0、28、42天都旱现比较高的水平.结论 仔鼠脑、肝组织中砷及其甲基代谢物呈现剂量相关性分布.砷可通过胎盘屏障、血脑屏障对仔鼠产生不良影响,而乳汁屏障能够阻碍一定量的砷进入.
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