双酚A对雌性小鼠血清性激素及卵巢氧化损伤的影响

Effects of bisphenol A on serum sex hormone levels and ovarian oxidative damage in female mice

目的探讨双酚A(bisphenol A,BPA)对雌性小鼠血清性激素水平影响及卵巢氧化损伤作用。方法将30只1周龄健康SPF级昆明雌性小鼠按体重随机分为对照(玉米油)组和100、200 mg/kg BPA染毒组,每组10只。采用灌胃方式进行染毒,染毒容量为0.01 ml/g,每天1次,每周连续染毒5 d,共染毒12周。测定小鼠血清中雌二醇(E2)、孕酮(P)、卵泡刺激素(FSH)及卵巢细胞活性氧(ROS)的水平;通过免疫组化SP法检测卵巢Bcl-2及Bax蛋白的表达,并计算Bcl-2/Bax值。结果与对照组相比,各剂量BPA染毒组小鼠血清中E2、P的水平均降低,而FSH的水平均升高,差异均有统计学意义(P<0.05);且随着BPA染毒剂量的升高,小鼠血清中E2、P的水平均呈下降趋势,而FSH的水平呈上升趋势。与对照组相比,各剂量BPA染毒组小鼠卵巢细胞ROS的水平均较高,差异有统计学意义(P<0.05);且随着BPA染毒剂量的升高,小鼠卵巢细胞ROS的水平呈上升趋势。与对照组相比,各剂量BPA染毒组小鼠卵巢细胞BAX蛋白的表达水平均较高,而Bcl-2蛋白的表达水平及Bcl-2/BAX值均降低,差异均有统计学意义(P<0.05);且随着BPA染毒剂量的升高,小鼠卵巢细胞BAX蛋白的表达水平呈上升趋势,而Bcl-2蛋白的表达水平及Bcl-2/BAX值均呈下降趋势。BPA染毒组卵巢颗粒细胞和卵泡的形态结构病理学变化明显。结论BPA可致小鼠卵巢组织发生明显的氧化损伤。

Objective To understand the effects of bisphenol A(BPA)on serum sex hormone levels and ovarian oxidative damage of female mice.Methods Thirty healthy SPF female Kunming mice aged one week were randomly divided into three groups according to body weight,the control group(corn oil),100 mg/kg and 200 mg/kg BPA group,10 mice in each group.The rats were treated with BPA through gavage,once a day,five times a week,for 12 weeks.The dose was 0.01 ml/g.The levels of estradiol(E2),progesterone(P)and follicle stimulating hormone(FSH)in the serum were measured,and the pathological examination of ovary was conducted.The 2’,7’-dihydrodichlorofluorescein diacetate(DCFH-DA)was used as the specific probe of reactive oxygen species(ROS),the fluorescence intensity of oxidized dichlorofluorescein(DCF)in cells was detected by flow cytometry by taking mouse ovary cells as the materials,so the level of ROS in cells could be reflected.The expression of Bcl-2 and Bax protein was detected by immunohistochemical SP method,and the results were analyzed by image analysis.The results of immunohistochemical staining were transformed into numerical values for quantitative analysis,and then the Bcl-2/BAX ratio was calculated.Results Compared with the control group,serum E2 and P levels in 100 mg/kg and 200 mg/kg BPA groups were both decreased,and the FSH level increased significantly(P<0.05).With the exposure dose increase of BPA,the content of E2 and P presented a downward trend,and the content of FSH increased.The fluorescence intensity(ROS)of ovarian cells in the 100 mg/kg and 200 mg/kg BPA group significantly increased compared with the control group(P<0.05).Besides,the expression of Bcl-2 protein in ovarian cells of 100 mg/kg and 200 mg/kg BPA groups were lower than that of the control group,but the expression of Bax protein was significantly higher than that of the control group(P<0.05).In addition,the ratios of Bcl-2/Bax in ovarian cells of 100 mg/kg and 200 mg/kg BPA groups were significantly lower than that of the control group(P<0.05).Compared with the control group,in 100 mg/kg and 200 mg/kg BPA groups,pathological changes were observed both in ovarian granulosa cells and follicular morphological structure.Conclusion BPA can increase the E2 and P levels in serum and decrease the FSH level,and it can increase the content of ROS and increase the expression of Bax protein in mouse ovary cells,cause oxidative damage in mouse ovarian tissue.