大豆异黄酮对新生儿期大鼠子宫发育和雌激素受体表达的影响

Effects of Lactational Exposure to Soy Isoflavones on Uterine Development and Estrogen Receptor Expression in Neonate Rat

目的研究母鼠暴露于大豆异黄酮对新生儿期大鼠子宫发育及雌激素受体表达的影响。方法将母鼠及其仔鼠随机分至6组,母鼠的大豆异黄酮暴露剂量分别为0、10、50、100、150、200mg/kgBW（i.g.）,暴露时间为产后第5至10天（PND5~10）。在PND11处死雌性仔鼠,称量子宫重量并进行病理学检查,利用ELISA方法测定血清雌二醇（E2）和孕酮（P）浓度,利用RT-PCR方法测定子宫中雌激素受体（ER）mRNA的表达。结果与对照组比较,大豆异黄酮150、200mg/kgBW剂量组仔鼠的子宫/体重比显著增加,子宫内膜增厚的差异有统计学意义（P〈0.05）;血清E2浓度明显高于对照组,SIF150组升高幅度最大,但各处理组血清P浓度呈下降趋势;100、150、200mg/kgBW剂量组仔鼠的子宫ERmRNA表达降低的差异有统计学意义（P〈0.05）。结论大豆异黄酮经母鼠暴露,可刺激雌性仔鼠的子宫发育,这种雌激素样效应至少与该物质对血液性激素和子宫ERmRNA表达的调节作用有关。

Objective To study the effects of lactational exposure to soy isoflavones （SIF） on uterine development and estrogen receptor expression in neonate rats. Methods 42 maternal rats were randomly divided into six groups with seven dams in each group so that every maternal rat could breed about 8 to 10 litters, which contained 4 to 6 female litters. After postnatal day 5 to 10 （PND 5 - 10）, maternal rats were gavaged SIF at the doses of 0, 10, 50, 100, 150, 200 mg/kg BW in different treatment groups, respectively. On PND 11, female litters were killed and their uterine were removed for pathological, evaluation after weighing. The concentrations of serum estradiol （E2） and progesterone （P） were detected by ELISA, and the expression of estrogen receptor mRNA （ER mRNA） in uerine were measured by RT-PCR. Results The ratios of uterine weight to body weight and heights of endometrium at the doses of 150 and 200 mg/kg BW groups were higher than those of control groups （ P 〈 0.05）. Serum E2 concentrations in rats treated with SIF were higher than those of untreated rats, while P concentrations in treatment groups were lower than those of control group. At the doses of 100, 150 and 200 mg/kg BW groups, ER mRNA expressions decreased significantly when compared with control groups （P 〈 0.05 ）. Conclusion Lactational exposure to soy isoflavones could induce abnormal development of uterus in neonate rats, which mechanisms could be associated with modification of SIF on serum hormone and ER mRNA expression.