双酚A和邻苯二甲酸二丁酯暴露对雌性幼鼠青春期发育的影响

Impact of exposure to bisphenol A and dibutyl phthalate on puberty development of female young rats

目的研究双酚A(BPA)和邻苯二甲酸二丁酯(DBP)对雌性幼鼠青春期发育的影响。方法将64只21日龄SD雌性幼鼠用随机数字表法分为BPA干预组(BPA 0.25 mg/kg灌胃10 d)、DBP干预组(DBP 50 mg/kg灌胃10 d)、BPA+DBP干预组(BPA 0.20 mg/kg+DBP 40 mg/kg灌胃10 d)、雌二醇(E_(2))组(E_(2)0.1 mg/kg灌胃10 d)、BPA空白对照组(10 mL/kg不含BPA的玉米油溶液灌胃10 d)、DBP空白对照组(10 mL/kg不含DBP的玉米油溶液灌胃10 d)、正常对照组(不做任何处理)和溶剂组(10 mL/kg玉米油溶液灌胃10 d),每组8只。观察幼鼠阴道开口时间(VOD),收集子宫、卵巢进行病理学检查,采用酶联免疫吸附试验检测血清卵泡刺激素(FSH)、黄体生成素(LH)和Kisspeptin水平,采用实时荧光定量PCR检测下丘脑KISS-1、G蛋白偶联受体54(GPR54)和卵巢雌激素受体(ER)α、ERβmRNA表达水平。结果与正常对照组和溶剂组相比,BPA干预组和E_(2)组VOD提前,差异有统计学意义(P<0.05)。BPA干预组血清LH、FSH、LH/FSH、E_(2)、Kisspeptin水平明显高于BPA空白对照组,差异有统计学意义(P<0.05)。E_(2)组血清LH、FSH和Kisspeptin水平明显低于正常对照组和溶剂组,差异有统计学意义(P<0.05)。BPA干预组下丘脑KISS-1、GPR54 mRNA表达水平明显高于BPA空白对照组,差异有统计学意义(P<0.05)。E_(2)组下丘脑KISS-1和卵巢ERβmRNA表达水平明显低于正常对照组和溶剂组,差异有统计学意义(P<0.05)。结论BPA暴露可致雌性幼鼠性早熟,其致病机制可能与下丘脑Kisspeptin-KISS-1/GPR54-促性腺激素释放激素信号传导和下丘脑-垂体-性腺轴提前激活有关。

Objective To evaluate the impact of exposure to bisphenol A(BPA)and dibutyl phthalate(DBP)on puberty development of female young rats.Methods A total of 64 SD female young rats aged 21 days were divided into BPA intervention group(BPA 0.25 mg/kg gavage for 10 d),DBP intervention group(DBP 50 mg/kg gavage for 10 d),BPA+DBP intervention group(BPA 0.20 mg/kg+DBP 40 mg/kg gavage for 10 d),estradiol(E_(2))group(E_(2)0.1 mg/kg gavage for 10 d),BPA blank control group(10 mL/kg corn oil solution without BPA gavage for 10 d),DBP blank control group(10 mL/kg corn oil solution without DBP gavage for 10 d),normal control group(without any treatment)and solvent group(10 mL/kg corn oil solution gavage for 10 d)by random number table method,8 cases in each group.Observed the vaginal opening day(VOD)of young rats,collected uterus and ovaries for pathological examination.Enzyme-linked immunosorbent assay was used to detect serum follicle stimulating hormone(FSH),luteinizing hormone(LH)and Kisspeptin levels.Real-time fluorescent quantitative PCR was used to detect the expression levels of hypothalamic KISS-1,G protein-coupled receptor 54(GPR54)and ovarian estrogen receptor(ER)αand ERβmRNA.Results Compared with normal control group and solvent group,the VOD of BPA intervention group and E_(2) group was earlier,and the differences were statistically significant(P<0.05).The levels of serum LH,FSH,LH/FSH,E_(2) and Kisspeptin in BPA intervention group were significantly higher than those in BPA blank control group,and the differences were statistically significant(P<0.05).The serum levels of LH,FSH and Kisspeptin in E_(2) group were significantly lower than those in normal control group and solvent group,and the differences were statistically significant(P<0.05).The expression levels of hypothalamic KISS-1 and GPR54 mRNA in BPA intervention group were significantly higher than those in BPA blank control group,and the differences were statistically significant(P<0.05).The expression levels of hypothalamic KISS-1 and ovarian ERβmRNA in E_(2) group were significantly lower than those in normal control group and solvent group,and the differences were statistically significant(P<0.05).Conclusion BPA exposure could cause precocious puberty in f emale young rats,and its pathogenic mechanism might relate to hypothalamic Kisspeptin-KISS-1/GPR54-gonadotropin releasing hormone signaling and early activation of the hypothalamic-pituitary-gonadal axis.