孕期暴露双酚A对子代雌性大鼠卵巢类固醇激素合成的影响

Effects ofexposure to bisphenol A in utero on ovarian steroid hormone synthesis in female offspring rats

目的 研究孕期双酚A（BPA）暴露对子代雌性大鼠卵巢类固醇激素合成的影响。方法 选择SPF级3月龄的健康成年SD大鼠,按雌雄比为2∶1同笼配种。取妊娠大鼠20只,随机分成4组,于妊娠第5天~第20天,分别按0,10,50,250mg/（kg·d）BPA进行灌胃染毒。母鼠正常分娩,观察雌性仔鼠生长发育变化至10周龄,确定发情间期后处死动物。ELISA法测定血清中卵泡刺激素（FSH）、黄体生成素（LH）、孕酮（P4）、雌二醇（E2）及睾酮（T）水平;实时PCR测定卵巢中类固醇激素急性调节蛋白（StAR）、胆固醇侧链裂解酶（P450scc）、3β羟类固醇脱氢酶（3β-HSD）、细胞色素P450-17α羟化酶（P450-17α）、17β-羟类固醇脱氢酶（17β-HSD）、芳香化酶（P450arom）mRNA的基因表达。结果 出生28~36d期间,50和250mg/kg组体质量与对照组比较明显增加,差异有统计学意义（P〈0.05）;各剂量组与对照组相比,T水平明显下降,差异有统计学意义（P〈0.05）;50和250mg/kg组与对照组相比,LH、FSH、E2水平明显减少,差异有统计学意义（P〈0.05））;各剂量组卵巢中17β-HSD mRNA的基因表达与对照组比较明显降低,差异有统计学意义（P〈0.05）;50和250mg/kg组P450arom mRNA的基因表达与对照组比较明显降低（P〈0.05）,差异有统计学意义。结论 孕期暴露BPA对子代雌性大鼠卵巢中类固醇激素合成酶的基因表达有一定的影响,可能影响类固醇激素合成,进而影响下丘脑-垂体-卵巢轴的正常调节。

Objective To study the effects of exposure to bisphenol A （BPA） on ovarian steroid hormone synthesis in female offspring rats. Methods 20 pregnant rats were randomly divided into four groups. The rats were gavaged respectively at 0, 10, 50 and 250 mg/（kg ·d） from days 5 to 20 of gestation. The female offsprings were killed at 10-weeks, when they were determined at diestrous stage. The levels of follicle- stimulating hormone （FSH）, luteinizing hormone （LH）, progesterone （P4） , estradiol （E2） and testosterone （T） in serum were determined by ELISA method. The gene expressions of ovarian steroid hormones acute regulatory protein （ StAR ）, cholesterol side-chain cleavage enzyme （ P450scc ）, 3β-hydroxysteroid dehydrogenase （3β-HSD）, cytochrome P450 17α-hydroxylase（P450 17α）, 17β hydroxy steroid dehydrogenase （17β-HSD） and aromatase（P450arom）were measured using real-time PCR. Results BPA （50 and 250 mg/kg） exposure in utero significantly incresaed body weight from PND 28 to 36. The gene expressions of 17β-HSD were significantly decreased at BPA groups compared with the control group （P 〈 0.05） . And The gene expressions of P450arom at 50 and 250 mg/kg BPA groups increased significantly compared with the control group. Levels of T were significantly decreased （P〈~ 0.05） at BPA groups compared with the control group. Levels of LH, FSH and E2 were significantly reduced （P 〈0.05） at 50 and 250 mg/kg BPA groups. Conclusions BPA exposure in utero could affect the gene expression of ovarian steroid hormone synthesis enzymes in female offspring rats, and affect steroid hormone synthesis. As a result, BPA exposure in utero could affect the function of thalamus-pituitary-ovary axis.