【摘要】 [目的]研究DDT类农药同分异构体和同系物的联合雌激素效应。[方法]用重组人雌激素受体(hER)基因酵母细胞(W303-1A/hER-ERE-LacZ)评价DDT农药同分异构体和同系物的雌激素活性。将终浓度为10-9~10-15的17β-雌二醇、终浓度为10-3~10-9的p,p’-DDT、o,p’-DDT和p,p’-DDD、p,p’-DDE加入酵母细胞培养液,作用4h,通过定量测定β-半乳糖苷酶的活性表示DDT农药的雌激素作用强度。[结果]o,p’-DDT和p,p’-DDD能像配体一样与hER结合,发挥雌激素效应,并且具有剂量效应关系,回归方程分别为=1.4553x2+47.366x+333.31和=-0.1658x3-3.6506x2-23.176x-25.809。同分异构体间比较,o,p’-DDT相对雌激素活性较强,EC50为2.04×10-7mol/L,而p,p’-DDT的EC50为3.71×10-4mol/L,两者雌激素作用呈协同效应,联合效应相加指数(AI)=0.74(>0);同系物间比较,p,p’-DDD雌激素活性明显较强,EC50为2.78×10-7mol/L,而p,p’-DDE的EC50为5.88×10-5mol/L,两种同系物的雌激素作用呈拮抗效应,AI=-1.13(<0)。[结论]o,p’-DDT和p,p’-DDD是经雌激素受体(ER)介导的环境雌激素,o,p’-DDT与p,p’-DDT同分异构体间雌激素活性具有协同效应,p,p’-DDD和p,p’-DDE同系物间雌激素活性呈拮抗效应。更多还原

【Abstract】 Objective To study the combined estrogenic effects of the isomers and the homologue of DDT pesticide. Methods Using a recombinant human estrogen receptor gene yeast cell to assess the estrogenic activity of isomers and the homologue of DDT pesticides. The different concentrations of 17β-estradiol and individual DDT isomers and homologue such as p,p’-DDT,o,p’-DDT,p,p’-DDD and p,p’-DDE and their mixtures were added to yeast cultures,and then estrogenic activity was measured by quantification of β-galactosidase after 4 hours culture. Results o,p’-DDT and p,p’-DDD have the ability to play an estrogenic effects to bind hER like a ligand and a dose dependent model existed between the estrogenic effects and the DDT concentration; the regression equations are = 1.4553x2 + 47.366x + 333.31 and = -0.1658x3-3.6506x2-23.176x -25.809 respectively. Compared with that of p,p’-DDT isomer with its EC50 3.71×10-4 mol/L,the relative activity of o,p’-DDT with its EC50 2.04×10-7 mol/L was more estrogenic,and the estrogenic effects of isomers showed a synergism,AI=0.74(>0). p,p’-DDD was more estrogenic with its EC50 2.78×10-7 mol/L compared to p,p’-DDE with its EC50 5.88×10-5 mol/L,and an antagonism was shown between the homologues,AI=-1.13(<0). Conclusion o,p’-DDT and p,p’-DDD are environmental estrogen mediated by ER. The joint estrogenic effect of isomers,p,p’-DDT,o,p’-DDT showed synergic,and that of homologues,p,p’- DDD and p,p’-DDE,showed antagonistic respectively.更多还原