To explore the combined toxic effect of formaldehyde and DEHP on learning and memory of mice and the mechanism, Kunming mice were randomly divided into 14groups: (1) the control group; (2) FA (formaldehyde) group: 0.5mg/m3, 1mg/m3, 3mg/m3; (3) DEHP group: 5mg/kg, 50mg/kg, 500mg/kg; (4) the joint exposure: 0.5mg/m3+5mg/kg, 1mg/m3+50mg/kg, 3mg/m3+500mg/kg; (5) VE group: saline+VE (100mg/kg), FA3.0mg/m3+ VE, DEHP500mg/kg + VE, FA3.0mg/m3+ DEHP500mg/kg + VE. The mice of FA and joint exposure groups were exposed to gaseous formaldehyde for 8h everyday (continuous exposure for 5days, interval for two days), and the mice of DEHP and joint exposure groups were gavaged with DEHP solution. Besides, blocking groups were also gavaged VE solution (100mg/kg) everyday. Their behaviors of learning and memory were tested by Morris water maze experiment. Then the change of biological indicators including oxidative damage, ROS, MDA, TNF-α, IL-β, and 5-HT, etc, was detected in the cerebral tissue. Results showed that Morris water maze test in space training and learning indicated that escape latency significantly extended in 3.0mg/m3 of formaldehyde and 500mg/kg of DEHP treatment group, 1.0mg/m3+50mg/kg and 3.0mg/m3+500mg/kg of the combined treatment groups (P<0.05). Compared with single exposure groups, escape latency significantly extended in the moderate and high dose of combined treatment groups (P<0.05). In space exploration experiments, the proportion of time of the target quadrant in 1.0mg/m3 and 3.0mg/m3 of formaldehyde treatment groups, the 500mg/kg of DEHP treatment group, and 1.0mg/m3+50mg/kg, 3.0mg/m3+500mg/kg of the combined treatment groups were less than the control group (P<0.05). The proportion of time of the target quadrant in combined treatment groups were significantly decreased compared with single exposure (P<0.05). Compared with control group,the contents of ROS and MDA in 1.0mg/m3 and 3.0mg/m3 of formaldehyde, 50mg/kg and 500mg/kg of DEHP groups and all the joint exposure groups were increased, while the contents of GSH decreased in 3.0mg/m3of formaldehyde, 500mg/kg of DEHP groups and all the joint exposure groups decreased. Compared with formaldehyde or DEHP exposure groups, the contents of GSH in joint exposure groups were significantly decreased (P<0.01). The expression level of inflammatory factor TNF-α and IL-β were also significantly increased, and Caspase-3 was activated. The content of 5-HT in 3.0mg/m3+500mg/kg of joint exposure group was significantly decreased (P<0.01). 0.5mg/m3 of formaldehyde had little effect on mice and their behaviors of learning and memory didn't obviously change. This study shows that 1.0mg/m3 and 3.0mg/m3 of formaldehyde and 500mg/kg of DEHP treatment group and 1.0mg/m3+50mg/kg, 3.0mg/m3+500mg/kg of the combined treatment groups could cause Kunming mice oxidative damage and inflammation. The joint exposure of formaldehyde and DEHP has synergistic effect. And VE could protect brain tissue by reducing Oxidative stress, inflammation, the level of Caspase-3, and increasing the content of 5-HT.%为探讨甲醛职业气态暴露和邻苯二甲酸二乙基己酯(DEHP)经口灌胃联合染毒对小鼠学习记忆能力的影响,本实验以雄性昆明小鼠为研究对象,开展甲醛与DEHP职业暴露实验研究.实验分组为:(1)对照组;(2)FA(甲醛)组:0.5,1,3mg/m3;(3)DEHP组:5,50,500mg/kg;(4)联合组:0.5mg/m3+5mg/kg,1mg/m3+50mg/kg,3mg/m3+500mg/kg;(5)阻断组:生理盐水+VE(维生素E)(100mg/mL),FA3.0mg/m3+VE,DEHP500mg/kg+VE,FA3.0mg/m3+DEHP500mg/kg+VE.FA组和联合组吸入气态甲醛染毒8h,5+2模式(5d持续暴露,间隔2d,暴露2周),DEHP组和联合组经口灌胃不同浓度的DEHP溶液,持续14d.此外,阻断组每天用100mg/mL的VE灌胃小鼠(灌胃剂量10mg/(kg·d)).每日染毒结束后,进行水迷宫测试.检测脑组织中ROS、MDA、TNF-α、IL-β和5-HT等生理指标的变化.结果表明:在定位导航实验中,甲醛和DEHP均可影响小鼠逃避潜伏期,随着染毒剂量的增大,潜伏期延长.联合染毒组较同等剂量的单独染毒组尤为明显.在空间探索实验中,与对照组比较,甲醛1,3mg/m3和DEHP500mg/kg及联合组1mg/m3+50mg/kg和3mg/m3+500mg/kg在目标象限游泳时间缩短(P<0.05);联合组在目标象限的游泳时间与甲醛 、DEHP单独染毒组比较均明显减少(P<0.05).甲醛1.0,3.0mg/m3和DEHP50mg/kg,500mg/kg及联合组1.0mg/m3+50mg/kg,3.0mg/m3+500mg/kg小鼠脑组织内ROS水平和MDA含量出现显著性上升,GSH水平出现显著下降(P<0.05),炎性因子TNF-α 和IL-β 表达水平也显著增加,细胞凋亡因子Caspase-3得到活化,神经递质5-HT含量在3.0mg/m3+500mg/kg组中明显降低(P<0.01).0.5mg/m3甲醛暴露组对小鼠影响不明显,各项指标未出现显著性变化,行为学亦没有明显变化.综上,甲醛1.0,3.0mg/m3和DEHP500mg/kg及联合1.0mg/m3+50mg/kg和3.0mg/m3+500mg/kg能使小鼠产生氧化损伤和炎症反应,ROS,MDA水平上升(P<0.05),GSH水平下降(P<0.05),炎症因子IL-β,TNF-α水平上升(P<0.05),Caspase-3水平上升(P<0.05),8-OHDG水平上升(P<0.05),神经递质5-HT水平下降(P<0.05).两者联合染毒具有一定的正协同作用.VE能够通过降低脑组织中氧化应激、炎症、细胞凋亡水平和增加神经递质含量对小鼠脑组织进行保护.
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