菌核净内分泌干扰作用研究

目的研究菌核净内分泌干扰作用(雌激素和抗雄激素活性作用)。方法通过不同实验终点探讨菌核净雌激素样作用:(1)每隔5天腹腔注射给予鲫鱼不同浓度菌核净(0、50、100和200mg/kg)诱导卵黄蛋白原(VTG)的产生,2周后收集雄性鲫鱼血浆和肝脏进行VTG检测;(2)人乳腺癌细胞(MCF-7细胞)中加入不同浓度的菌核净(10-10～10-4mol/L),作用3天后观察菌核净诱导细胞增殖情况;(3)雌性小鼠去势后给予不同浓度菌核净(0、125、250和500mg/kg),计算子宫脏器系数。Hershberger试验研究菌核净抗雄激素样作用:雄性大鼠去势后给予不同剂量的菌核净(0、30、60和120mg/kg),同时皮下注射雄性激素丙酮酸睾酮(TP),计算雄激素依赖组织的脏器系数。结果100mg/kg和200mg/kg菌核净能诱导雄性鲫鱼血VTG产生,200mg/kg菌核净能刺激雄性鲫鱼肝脏产生VTG,与阴性对照组相比,VTG含量差异均具有显著性(P<0.05);各剂量组菌核净对雄性鲫鱼血钙离子、血和肝总蛋白含量均无影响,但阳性对照E2能增高血钙离子水平;10-8、10-7和10-6mol/L菌核净能诱导MCF-7细胞增殖,与对照组相比,差异具有显著性(P<0.05);菌核净3个剂量组均能增加去势小鼠子宫脏器系数,其中250mg/kg组与阴性对照组比较差异具有显著性(P<0.05);60mg/kg和120mg/kg菌核净均能降低前列腺加精囊腺、肛提肌、球海绵体肌的脏器系数,与模型对照组比较,差异具有显著性(P<0.05)。结论菌核净具有雌激素和抗雄激素双重内分泌干扰作用。

Study on the endocrine disrupting effect of dimethachlon

Objective In order to study the endocrine disrupting effect of dimethachlon (NDPS)(estrogenic and antiandrogenic activity). Methods To investigate the estrogenic activity of NDPS by different experiments:(1) Carassius auratus received intraperitoneal injections with NDPS (0,50,100 and 200mg/kg) at regular intervals(5 days) for the synthesis of VTG,The estrogenic effects of the treatment were investigated on VTG in plasma and liver measured by ELISA at 14th. (2) Added the positive control E2(10 -7 mol/L),and NDPS (10 -10 mol/L,10 -9 mol/L,10 -8 mol/L,10 -7 mol/L,10 -6 mol/L,10 -5 mol/L and 10 -4 mol/L) to MCF-7 cells and determinated the proliferation of MCF-7 cells with MTT assay. (3) female mices 18-22 g in weight were castrated,then they were gavaged daily for 5 days with E2(500μg/kg) or NDPS (0,125,250 and 500mg/kg) or peanut oil,then uterus was removed and weighed at 6th. Hershberger assay:male SD rats of 4 weeks age were castrated,after 2 weeks,the other groups were dosed daily for 7 days with testosterone propionate(1mg/kg,sc) plus peanut oil(p.o) or plus NDPS (30mg/kg,60mg/kg and 120mg/kg,p.o) but one group of castrated rats were subcutaneously injected with peanut oil plus(sc) peanut oil(p.o) as control. Then,the adrenals,prostate,glans penis,seminal vesicle,levator ani and bulbocavernosus muscles were removed and weighed. Results Compared with control group. There have significantly increase in the plasma VTG concentration in 10mg/kg of E2 treatment group as well as in 100mg/kg and 200mg/kg of NDPS 14d after injection. In addition,a significantly increase in the liver VTG concentration was observed in the 200mg/kg of NDPS treatment group. There was no significant alteration of Ca 2+ ,total protein and liver protein content in plasma in all NDPS treatment groups,but E2 increased the plasma Ca 2+ level,that is higher than the control group.10 -8 mol/L,10 -7 mol/L and 10 -6 mol/L NDPS could stimulate the proliferation of MCF-7 cell,and there were significant differences compared with control group.All NDPS treatment groups could increase the weight of uterus,but only 250mg/kg group has signifgicant differences,compared with the control group. In Hershberger assay,relative weight of prostate,seminal vesicle,levator ani and bulbocavernous muscle in 60mg/kg group and 120mg/kg group were significantly decreased when compared with those in the control group. Conclusion NDPS exerts endocrine disrupting effect including estrogenic activity and antiandrogenic activity.