p,p’-DDE宫内暴露致子代SD大鼠糖耐量受损

Impaired glucose tolerance in offspring rat following in utero p,p'-DDE exposure

[目的]研究2,2-双(对氯苯基)-1,1-二氯乙烯(p,p’-DDE)宫内暴露对子代SD大鼠糖代谢的影响。[方法]将8~10周龄的性成熟雌、雄SD大鼠各16只按1∶1雌雄同笼交配,母鼠交配成功后,将孕鼠随机分为对照组和p,p’-DDE染毒组,每组各8只。孕第8~15天时,按100 mg/kg(以体重计)的剂量对染毒组孕鼠用p,p’-DDE连续灌胃8 d,对照组孕鼠给予5 m L/kg(以体重计)的等容积玉米油。足月孕鼠自由分娩,保留每窝雌雄仔鼠各5只。8周后,仔鼠称重过夜禁食,然后进行口服葡萄糖耐量实验,测定灌胃后0、30、60、120 min尾静脉血中的血糖水平并计算血糖曲线下面积。同时,灌胃前及灌胃后2 h进行眼眶采血,并用酶联免疫法测定眼眶血血清中的胰岛素水平。[结果]染毒组雄仔鼠的空腹血糖水平降低(t=3.94,P=0.011)。染毒组雌、雄仔鼠灌胃后30 min血糖水平均高于对照组(t=-2.876,P=0.016;t=-3.862,P=0.012),而灌胃后60 min和120 min的血糖水平均无改变(P>0.05)。同时,染毒组雌、雄仔鼠的血糖曲线下面积均较对照组高(t=-3.422,P=0.004;t=-2.804,P=0.038)。染毒组雌、雄仔鼠灌胃前(t=-3.33,P=0.008;t=-6.90,P=0.000)及灌胃后2 h(t=-5.19,P=0.000;t=-4.18,P=0.006)的血清胰岛素水平均高于对照组。[结论]p,p’-DDE宫内暴露可诱导子代SD大鼠糖耐量受损。

[Objective] To examine the effects of exposure to 2, 2-dichloroethene-1, 1-bis-（4-chlorophenyl）（p, p＇-DDE） in utero on glucose metabolism in offspring rats. [Methods] Pregnant rats were randomly divided into two groups with eight rats each and exposed to 5 m L/kg com oil（control） or 100 mg/kg p, p＇-DDE for eight days by gavage from gestation day（GD） 8 to 15. Eight weeks after birth, offspring rats were chosen from both the p, p＇-DDE-treated group and the control group and body weight was recorded. Oral glucose tolerance test was conducted following overnight fasting on all the offspring rats to determine glucose levels in tail vein blood, and the area under the curve of blood glucose was calculated at 0, 30, 60, and 120 min. Meanwhile, orbital blood samples were collected before and 2 h after oral administration of glucose for evaluating serum insulin levels by enzyme linked immunosorbent assay（ELISA）.[Results] The fasting blood glucose levels of the offspring male rats in the p, p＇-DDE group significantly reduced compared with the control group（t=3.94, P=0.011）. For female and male offspring rats, the blood glucose levels at 30 min after oral administration in the p, p＇-DDE group were significantly higher than those of the control group（t=-2.876, P=0.016; t=-3.862, P=0.012）. However,the levels of blood glucose for the two genders of offspring rats showed no significant changes after oral administration for 60 min or 120 min（P〈0.05）. The areas under the curve of blood glucose were significantly elevated in the offspring female and male rats of the p, p＇-DDE group（t=-3.422, P=0.004; t=-2.804, P=0.038） respectively. The fasting（t=-3.33, P=0.008; t=-6.90, P=0.000） and 2 h postprandial（t=-5.19, P=0.000; t=-4.18, P=0.006） serum insulin levels in both genders of offspring rats were significantly higher in the p, p＇-DDE group than those in the controls. [Conclusion] Exposure to p, p＇-DDE in utero may lead to glucose metabolism impairment in offspring rats.