【摘要】 目的观察邻苯二甲酸二乙基己酯(DEHP)与双酚A(BPA)联合染毒对大鼠肝脏损伤,探讨其氧化应激机制。方法无特定病原体级健康雄性SD大鼠随机分为对照组、DEHP组、BPA组和联合染毒组,每组8只。采用经口灌胃法,DEHP组大鼠予750 mg/kg体质量DEHP,BPA组大鼠予100 mg/kg体质量BPA,联合染毒组大鼠予750mg/kg体质量DEHP和100 mg/kg体质量BPA,连续染毒6周,每周7 d,1次/d。观察大鼠肝脏脏器系数和组织病理学改变,采用分光光度法检测大鼠肝脏组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力和过氧化氢(H2O2)、丙二醛(MDA)水平,采用实时荧光定量聚合酶链式反应法检测大鼠肝脏组织抗氧化基因核因子E2相关因子2(Nrf2)、血红素加氧酶-1(HO-1)、谷氨酸半胱氨酸连接酶催化亚基(Gclc)、硫氧还蛋白还原酶(Txnrd)、Sod3和Gpx1的相对表达水平。结果 DEHP组大鼠从第2周、联合染毒组大鼠从第3周开始体质量低于对照组(P<0.05)。DEHP组和联合染毒组大鼠肝脏质量及脏器系数均高于对照组(P<0.05)。肝脏组织病理学检查结果显示:DEHP组大鼠出现肝细胞坏死,BPA组大鼠肝细胞胞浆呈空泡样变,联合染毒组大鼠出现严重的炎细胞浸润。与对照组比较,3个染毒剂量组大鼠肝脏组织SOD和GSH-Px活力均下降(P<0.05),H2O2水平均升高(P<0.05);BPA组和联合染毒组大鼠肝脏组织MDA水平均升高(P<0.05)。与对照组比较,3个染毒组大鼠肝脏Nrf2、HO-1和Gpx1 mRNA相对表达水平均下降(P<0.05),DEHP组和联合染毒组大鼠肝脏Gclc、Txnrd和Sod3mRNA相对表达水平均下降(P<0.05);联合染毒组大鼠肝脏Nrf2、HO-1、Gclc、Txnrd和Sod3 mRNA相对表达水平均低于BPA组(P<0.05)。结论本研究条件下,DEHP、BPA单独及联合染毒均可导致大鼠肝脏损伤,联合作用大于单独作用,DEHP的影响大于BPA;DEHP和BPA所致大鼠肝脏损伤与Nrf2信号通路有关。更多还原

【Abstract】 Objective To observe the hepatic injury induced by combined exposure to diethylhexyl phthalate( DEHP) and bisphenol A( BPA) in rats and explore the mechanism of oxidative stress. Methods Thirty-two specific pathogen free healthy male SD rats were randomly divided into control group,DEHP(750 mg/kg body weight) group,BPA(100 mg/kg body weight) group and combined exposure group,with 8 rats in each group. The rats were gavaged once per day,7 days per week,for 6 weeks. The changes of liver organ coefficient and histopathology were observed. The activities of superoxide dismutase( SOD), glutathione peroxidase( GSH-Px) and the levels of hydrogen peroxide( H2 O2),malondialdehyde( MDA) were detected by spectrophotometry. The relative mRNA expression of antioxidant gene nuclear factor erythroid-2 related factor 2( Nrf2),heme oxygenase-1( HO-1),glutamate cysteine ligase catalytic subunit( Gclc),thioredoxin reductase( Txnrd),superoxide dismutase 3( Sod3) and glutathione peroxidase 1( Gpx1) in liver tissue were examined by real-time fluorescent quantitative polymerase chain reaction. Results The body weight of DEHP exposure group was lower than that of control group from the beginning of the 2 nd week( P < 0. 05),and the body weight of combined exposure group was lower than control group from the beginning of the 3 rd week( P < 0. 05). The liver mass and organ coefficients in DEHP group and combined exposure group were significantly higher than that of control group( P <0. 05). The results of pathology examination showed that there was necrosis of liver cells in DEHP group,vacuolar degeneration in cytoplasm of BPA group,and severe inflammatory cell infiltration in combined exposure group. The activity of SOD and GSH-Px of each exposure group was reduced( P < 0. 05),the H2 O2 level of each exposure group was increased(P < 0. 05),meanwhile the MDA level in the liver tissue of the BPA group and the combined exposure group increased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1 and Gpx1 in each exposure group were decreased( P < 0. 05),the relative mRNA expression of Gclc,Txnrd and Sod3 in DEHP group and mixed exposure group were decreased compared with the control group( P < 0. 05). The relative mRNA expression of Nrf2,HO-1,Gclc,Txnrd and Sod3 in combined exposure group were decreased compared with the BPA group( P < 0. 05).Conclusion Under the conditions of this study,DEHP and BPA alone or in combination could cause hepatic injury. The combined effect was greater than single effect. The effect of DEHP was greater than that of BPA. The liver injury induced by DEHP and BPA was related to Nrf2 signaling pathway.更多还原