p,p’-DDE和β-BHC联合染毒对孕小鼠生殖及其胎仔发育的影响

Study on reproductive and developmental toxicity of the pregnant mice and their foetus co-administered by p,p'-DDE and beta-BHC

目的研究p,p＇-DDE和β-BHC联合染毒对孕小鼠生殖和胎仔发育的影响.方法对孕12～14天小鼠每天联合灌胃不同剂量的p,p＇-DDE和β-BHC（各1、5、10mg/kg bw）,并设植物油溶剂对照组,采用磁性分离酶联免疫法检测孕鼠血清雌二醇（E2）和孕酮（P）含量,RT-PCR检测小鼠胎盘组织中雌激素受体（α-ER）、促性腺激素释放激素（GnRH）和β-内啡肽（β-EP）mRNA表达水平.结果①生殖影响：随染毒剂量加大母鼠子宫剥离重和子宫腔内液增加,子宫着床数减少,胎仔肛殖距和雌雄比增加,孕鼠血清中雌二醇和孕酮水平上升,胎盘组织α-ER和GnRH mRNA表达上调而β-EP mRNA表达下调,且均呈现剂量依赖性关系,差异有显著性（P＜0.05）.②发育影响：随染毒剂量增加孕鼠体重增长减少,肝脏的脏器系数增加,活胎数下降,不良妊娠结局（死胎、吸收胎和畸形数）增多,雌胎数所占比例加大,均呈剂量效应关系,差异有显著性（P＜0.05）.结论p,p＇-DDE和β-BHC可干扰孕小鼠生殖功能,导致生殖和发育障碍,造成雌雄比例失衡.

Objective To explore effects of p, p＇-DDE and β-BHC on reproduction anti development in mice. Methods The pregnant Kunming SPF mice of 12 to 14 days were co-administered by oral gavage for 3 days at different concentrations of 0, 1,5 and 10mg/kg bw of p, p＇-DDE and β-BHC. The concentrations of estradiol （E2） and progesterone （P） in scra of the dosed mice were determined by the Serozyme kits （Bio-Ekon bioteehnology Co. , Beijing, China）, following the procedures described by the manufacturer. RT-PCR was employed to detect abundant expression of alphaestrogen receptor （α-ER） gonadotropin releasing hormone （GnRH） and beta-endorphin （β-EP） mRNA in placentae. Results （ 1 ） Reproductive effects： with increase of the administered p, p＇-DDE and β-BHC, the organ coefficient of uterus and its intraluminal fluid increased, the untcrine nidation quantity decreased, the anogenital distance （AGD） anti ratio of female to male raised,the concentration of estradiol and progesterone in sera of the dosed mice went up, and the abundant expression of α-ER and GnRH mRNA fised while β-EP dropped in placentae in a dose-dependant manner. Significant difference of these indexes were found between the treat groups and control （P 〈 0.05）. （2）Developmental effects： with increase of the administered p, p＇-DDE and β-BHC ,the gained weights of pregnant mice reduced, organ coefficient of liver increased,the quantity of live foetus decreased, the times of adverse pregnancy outcome went up, and the percent of female foetus increased. They all presented a dose-effect relation and significance of difference （ P 〈 0.05）. Conclusion p,p＇- DDE and β-BHC disrupt reproductive function, thereby result in dysreproduetion and maldevelopment, and unbalance of ratio of female to male.