Liu Zhaoping, Zhang Xiaopeng, Li Li, Zhang Wenzhong, Cui Wenming, Song Yan, Wang Wei, Jia Xudong, Li Ning, Yan Weixing
Department of Food Toxicology, Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
Basic Clin Pharmacol Toxicol. 2008 Mar;102(3):317-24. doi: 10.1111/j.1742-7843.2007.00172.x. Epub 2007 Nov 28.
To examine effects of lactational exposure to soy isoflavones on female reproductive system, soy isoflavones, 0 (control), 10, 50, 100, 150 or 200 mg/kg body weight, were administered to maternal rats by gavage daily during postnatal days 5-10. Ten female litters were killed on day 11. Uterine and ovary weights, serum oestradiol and progesterone concentrations, proliferating cell nuclear antigen, mRNA expressions of oestrogen receptor, androgen receptor and progesterone receptor in uterus or ovary were measured. When compared to the control group, litters in the 150 and 200 mg/kg body weight groups had significantly higher ovary and uterine weights (P < 0.05). Endometrial thickness was also significantly increased. Isoflavone-treated groups had increased proliferating cell nuclear antigen staining in comparison to the control group. Litters in the 50, 150 and 200 mg/kg body weight groups had significantly higher oestradiol concentration while lower progesterone concentrations than those in the control group (P < 0.05 or P < 0.01). All soy isoflavone-treated groups had androgen receptor mRNA expressions in ovary and uterus comparable to the control group. Progesterone receptor mRNA expression in the 150 and 200 mg/kg body weight groups was significantly lower than that in control group (P < 0.01). However, ovaries in the 150 and 200 mg/kg body weight groups had significantly higher oestrogen receptor mRNA expression while the uterus in these two treatment groups had significantly lower expressions, when compared to the control group (P < 0.05 or P < 0.01). In conclusion, lactational exposure to isoflavones could result in oestrogen-like actions on the reproductive system of neonate female rats, which mechanisms may be, at least, involved with modifications of hormone production and steroid receptor transcription in the reproductive system.
为研究哺乳期暴露于大豆异黄酮对雌性生殖系统的影响，在出生后第5至10天，每天通过灌胃法给母鼠施用0（对照）、10、50、100、150或200毫克/千克体重的大豆异黄酮。在第11天处死10窝雌性幼崽。测量子宫和卵巢重量、血清雌二醇和孕酮浓度、增殖细胞核抗原、子宫或卵巢中雌激素受体、雄激素受体和孕酮受体的mRNA表达。与对照组相比，体重为150和200毫克/千克组的幼崽卵巢和子宫重量显著更高（P<0.05）。子宫内膜厚度也显著增加。与对照组相比，异黄酮处理组的增殖细胞核抗原染色增加。体重为50、150和200毫克/千克组的幼崽雌二醇浓度显著高于对照组，而孕酮浓度低于对照组（P<0.05或P<0.01）。所有大豆异黄酮处理组卵巢和子宫中的雄激素受体mRNA表达与对照组相当。体重为150和200毫克/千克组的孕酮受体mRNA表达显著低于对照组（P<0.01）。然而，与对照组相比，体重为150和200毫克/千克组的卵巢雌激素受体mRNA表达显著更高，而这两个处理组子宫中的雌激素受体mRNA表达显著更低（P<0.05或P<0.01）。总之，哺乳期暴露于异黄酮可能对新生雌性大鼠的生殖系统产生类雌激素作用，其机制可能至少与生殖系统中激素产生和类固醇受体转录的改变有关。
