大豆异黄酮和DEHP对雌性大鼠体内雌激素水平的影响

目的:探讨大豆异黄酮和邻苯二甲酸二(2-乙基己)酯(DEHP)对雌性大鼠体内雌激素的影响。方法:32只雌性SD大鼠按体质量随机分为4组,即大豆异黄酮(86 mg/kg)组、DEHP(68 mg/kg)组、大豆异黄酮(86 mg/kg)+DEHP(68 mg/kg)组和对照组(基础饲料),每组8只。受试物均混匀在大鼠饲料中,记录大鼠每周体质量及摄食量,喂养4周后处死,取各脏器称取质量。高效液相色谱法测定大鼠血清中DEHP含量,放射免疫法检测大鼠血清中雌二醇(E2)和睾酮(T)的水平。采用免疫组化检测大鼠子宫内膜ERα的表达量。结果:与对照组相比,各组雌鼠体质量增长无明显差异(P均>0.05);DEHP能明显增加雌性大鼠肝脏和脾脏系数(P<0.05); DEHP组和大豆异黄酮+DEHP组大鼠血清中DEHP的水平显著高于对照组(P<0.05),且二者联合作用组低于DEHP单独作用组(P<0.05)。各处理组对大鼠血清睾酮水平无显著影响,而大豆异黄酮+DEHP组和DEHP组大鼠血清中E2浓度低于对照组,差异有统计学意义(P<0.05)。免疫组化结果显示,大豆异黄酮、DEHP及二者联合作用组的大鼠子宫内膜ERα的表达与对照组相比差异均无统计学意义(P>0.05)。结论:DEHP能够显著增加雌性大鼠肝和脾的脏体比值且能显著降低血清中E2水平,大豆异黄酮可以一定程度上降低大鼠血清中DEHP的残留。

Effects of soybean isoflavone and DEHP on the hormone level in female rats

OBJECTIVE:To investigate the effects of soybean isoflavone and di-(2-ethylhexyl) phthalate(DEHP) on the hormone level in female rats.METHODS:Thirty-two female Sprague-Dawley ratswere randomly divided into 4 groups:86 mg/kg soybean isoflavone group,68 mg/kg DEHP group,isoflavone(86 mg/kg)+DEHP(68 mg/kg)group and control group,8 rats in each group. Food intake and body weight were recorded weekly,at the end of the fourth week,rats were sacrificed,bloodcollectedand viscera weighed. High performance liquid chromatography (HPLC) was used to measure serum DEHP content and radioimmunoassay method was used to assess serum estrogen and testosterone levels. The expression of ERα in endometrium was tested by immunohistochemistry.RESULTS:When compared to the control group,no significant difference was found in all of the treated groups with respect to weight gain (P value were all >0.05). DEHP significantly increased the organ/body ratio of spleen and liver when compared to the control group (P<0.05). The levels of serum DEHP in the DEHP group and isoflavone+DEHP group were significantly higher than that in the control group (P<0.05) and the isoflavone+DEHP group had significant lower DEHP level than the DEHP group (P<0.05). Furthermore,testosterone level was not significantly different among different groups,however,serum estrogen in isoflavone+DEHP and DEHP group was significantly lower than that in the control group (P<0.05). Immunohistochemistry suggested although 86 mg/kg soybean isoflavone group,68 mg/kg DEHP group and isoflavone+DEHP group had higher expresson level of ERα in rats’endometrium tissue,no significant difference was found among them(P>0.05). CONCLUSION:DEHP could significantly increase the organ/body ratio of the liver and spleen and it also could reduce serum estrogen level in female rats. Soybean isoflavone could reduce the residual serum DEHP to some extent.