母鼠孕期暴露双酚A对子代雌性大鼠性发育的影响

Effects of Bisphenol-A Exposure in Utero on Sexual Development of Female Offspring Rats

目的:研究母鼠孕期暴露双酚A(BPA)对子代雌性大鼠的性发育影响。方法:选择SPF级12周龄的健康成年SD大鼠,按雌∶雄为2∶1比例合笼。将妊娠大鼠20只,随机分成4组,于妊娠第5天至第20天,分别按0,10,50,250mg/(kg.d)进行灌胃染毒。母鼠正常分娩,雌性仔鼠出生28天开始观察阴道开口,第一次发情周期,此后连续观察动情周期变化,在第10周确定发情间期后处死动物。称量肝脏、肾脏、子宫、卵巢的重量,计算脏器系数;用ELISA法测血清中卵泡刺激素(FSH)、黄体生成素(LH)、孕酮(P4)、雌二醇(E2)及睾酮(T)水平。结果:各剂量组肝脏和肾脏重量与对照组相比有增加趋势,50 mg/kg组的肾脏重量和250 mg/kg组的肾脏系数有统计学意义(P<0.05);与对照组比较,10 mg/kg组阴道开口延迟,而250 mg/kg组阴道开口日龄提前,各剂量组阴道开口时体重增加(P<0.05);与对照组相比,BPA各剂量组子代雌性大鼠性周期均无明显影响;各剂量组与对照组相比,T水平明显下降(P<0.05);50mg/kg组与对照组相比,LH、FSH、E2水平明显减少(P<0.05),且P4水平有升高趋势;而250 mg/kg组上述指标与对照组比较差异无显著性(P>0.05)。结论:母鼠孕期暴露BPA可能导致子代雌性大鼠下丘脑-垂体-性腺轴的调节功能障碍,对其性发育功能造成一定影响。

Objective： To stud y the effects of Bisphenol-A（BPA）exposure i n uter o on sexual development of female offspr ing rats.Methods：Twenty pregnant healthy S prague Dawley rats,were randomly divide d into four groups.The pregnant rats we re gavaged respectively to 0,10,50 and 250 mg/kg BPA from day 5 to 20 of pregn a ncy.The female offspring rats at 28 day s were observed the vaginal opening,the first of estrous cyclicity.At 10-weeks the rats were killed at diestrous.Weig hts of liver,kidneys,uterus,ovarian w ere measured,and weight coefficient of tissues were calculated.The levels of f ollicle-stimulating hormone（FSH）,lutei nizing hormone（LH）,progesterone（P4）,estradiol（E2）and testosterone（T）in s erum were measured by ELISA method.Resu lts：Weight of kidney at 50 mg/kg group and kidney coefficient at 250 mg/kg grou p increased significantly（P〈0.05）.Com pared with control group,10 mg/kg group delayed vaginal opening,but 250 mg/kg group advanced vaginal opening.There we re no significant changes on estrous cyc licity（P〈0.05）.Compared with control l evels of T decreased significantly at BP A groups（P〈0.05）.Levels of FSH,LH and E2 decre ased significantly at 50 mg/kg group com pare with control group（P〈0.05）. P4 increase d significantly. There were no s ignificant differences on above index at 250 mg/kg group（P〈0.05）. Concl usion：BPA exposure in utero can dist urb the function of thalamus-pituitary-o varian axis,then affect the function of reproduction and develop ment in female offspring rats.