【作者】 朱嘉月；

【导师】 孙增荣；

【作者基本信息】 天津医科大学 ， 劳动卫生与环境卫生学， 2010， 硕士

【摘要】 目的：探讨邻苯二甲酸二丁酯(DBP)对青春期雌性大鼠生殖毒性作用及其作用机理。方法：21日龄SPF级雌性Sprague Dawley (SD)大鼠,按体重随机分为250mg/kg、500mg/kg、1000mg/kg三个剂量组和溶剂对照组(玉米油),连续8周灌胃染毒。当观察到大鼠阴道开口后,阴道脱落细胞学方法观察动情周期变化。染毒结束后,在动情前期股动脉取血,处死大鼠,称量子宫、卵巢湿重,计算脏器系数。放射免疫法检测血清中雌二醇(E2)、孕酮(P)、黄体生成素(LH)及促卵泡刺激素(FSH)的水平。取卵巢组织提取mRNA,实时荧光定量RT-PCR检测大鼠卵巢组织细胞色素P450芳香化酶(P450arom) mRNA、细胞色素P450胆固醇侧链裂解酶(P450scc) mRNA及过氧化物酶体增殖体激活受体γ(PPARy) mRNA表达水平。结果：(1)随着饲养时间的延长,大鼠体重逐渐增加,处理组之间大鼠体重变化有统计学差异(F=3.244,P<0.01),与对照组比较,500mg/kg剂量组大鼠体重高于对照组(P<0.05),250mg/kg及1000mg/kg剂量组大鼠体重与对照组无统计学差异(P>0.05),各剂量组间比较,500mg/kg剂量组大鼠体重高于1000mg/kg染毒组(P<0.05)；(2)各处理组子宫及卵巢脏器系数均无统计学差异(P>0.05)；(3)各处理组大鼠阴道开口时间无统计学差异(P>0.05)。各处理组大鼠动情周期总时间有统计学差异(F=25.599,P=0.001),与对照组比较,250mg/kg、500mg/kg、1000mg/kg剂量组大鼠动情周期总时间延长(P<0.05或P<0.01),各染毒剂量组之间动情周期总时间无统计学差异(P>0.05)。各处理组大鼠动情期时间有统计学差异(F=8.533,P=0.001),与对照组比较,250mg/kg、500mg/kg、1000mg/kg剂量组大鼠动情期时间延长(P<0.05或P<0.01),各染毒剂量组之间动情期时间无统计学差异(P>0.05)。各处理组大鼠动情前期、动情后期、动情间期时间无统计学差异(P>0.05)；(4)各处理组大鼠血清E2水平有统计学差异(F=13.502,P=0.001),与对照组比较,250mg/kg、500mg/kg、1000mg/kg剂量组大鼠血清E2水平增高(P<0.05或P<0.01),各剂量组间比较,250mg/kg染毒组大鼠血清E2水平高于500mg/kg及1000mg/kg剂量组(P<0.05及P<0.01)。各处理组大鼠血清P水平有统计学差异(F=4.306,P=0.014),与对照组比较,1000mg/kg剂量组大鼠血清P水平降低(P<0.05),与对照组比较,250mg/kg及500mg/kg剂量大鼠血清P水平无统计学差异。各处理组大鼠血清LH及FSH水平均无统计学差异(P>0.05)；(5)各处理组间大鼠卵巢P450arom mRNA表达水平有统计学差异(H=15.895,P<0.01),与对照组比较,250mg/kg、500mg/kg、1000mg/kg剂量组卵巢P450arom mRNA表达水平升高(P<0.01),各剂量组间卵巢P450arom mRNA表达水平无统计学差异(P>O.05)。各处理组间大鼠卵巢P450scc mRNA表达水平有统计学差异(H=15.591,P<0.01),与对照组比较,250mg/kg、500mg/kg、1000mg/kg剂量组大鼠卵巢P450scc mRNA表达水平降低(P<0.01),各剂量组间卵巢P450scc mRNA表达水平比较无统计学差异(P>0.05)；(6)各处理组间大鼠卵巢PPARγmRNA表达水平有统计学差异(H=12.650,P<0.01),与对照组比较,500mg/kg及1000mg/kg剂量组大鼠卵巢PPARγmRNA表达水平升高(P<0.05及P<0.01),各剂量组间比较,250mg/kg及500mg/kg剂量组PPARγmRNA表达水平低于1000mg/kg剂量组(P<0.05)。结论：(1)DBP可干扰了青春期雌性大鼠生殖内分泌功能,使大鼠动情周期延长,血清E2水平升高,血清P水平降低。(2)DBP雌性生殖毒性的机理可能与增加卵巢甾体激素合成过程中的关键酶P450arom mRNA表达,抑制P450scc mRNA表达有关。DBP也可通过激活卵巢颗粒细胞PPARy mRNA表达,引起雌性大鼠的生殖毒性。更多还原

【Abstract】 Objective:To study the reproductive toxicity and its related mechanisms of dibutyl phthalate (DBP) on puberty female rats.Methods:21-day-old Sprague Dawley (SD) female rats were randomly divided into 250mg/kg,500mg/kg and 1000mg/kg treatment groups and one control group(corn oil), the rats were administrated by gavage for 8 weeks. When observed vaginal opening, estrous cycles of rats were determined using vaginal exfoliative cytology examnation. By the end of 8 weeks’ treatment of DBP blood samples were collected from femoral artery in proestrus and all animals were sacrificed,the wet weights of the uterus and ovaries were recorded and organ coefficients were calculated, respectively. The serum levels of estradiol (E2), progesterone (P), luteinizing hormone (LH), follicle stimulating hormone (FSH) were examined using radioimmunoassay. The mRNA levels of aromatase, cholesterol side-chain cleavage enzyme and peroxisome proliferator-activated receptor y of ovaries were detected by real-time fluorescent quantitative polymerase chain reaction (RT-PCR).Results:(1) The body weight (BW) among treatment and control groups was statistically different (F=3.244, P<0.01), compared with the control group, BW of 500mg/kg group was higher significantly (P<0.05), there were no significant difference of BW between 250mg/kg, 1000mg/kg group and control group (P>0.05), BW of 500mg/kg group was significantly higher than that of 1000mg/kg group (P<0.05); (2) There was no significant difference of uterus and ovary organ coefficients among treatment and control groups (P>0.05); (3) There was no significant difference of vaginal opening time among treatment and control groups (P>0.05). The difference of period of estrous cycles among treatment and control groups was statistically significant (F=25.599, P=0.001), compared with the control group, the periods of estrous cycles in 250mg/kg,500mg/kg and 1000mg/kg groups were significantly longer than that of the control group (P<0.05 or P<0.01), but there were no significant differences of estrous cycles among the three treatment groups (P>0.05). The difference of period of estrus between treatment and control groups was statistically significant (F=8.533, P=0.001), compared with the control group, the periods of estrous in 250mg/kg, 500mg/kg and 1000mg/kg groups were longer than that of the control group(P<0.05orP<0.01), but there were no significant differences of estrus among three treatment groups (P>0.05); (4) There was significant difference of serum estradiol levels among treatment and cotrol groups (F=13.502,P=0.001), compared with the control group, the levels of serum estradiol were elevated statistically in 250mg/kg,500mg/kg and 1000mg/kg does groups (P<0.05 or P<0.01), the serum estradiol levels was higher in 250mg/kg group than those of 500mg/kg and 1000mg/kg groups (P<0.05andP<0.01).There were statistically significant differences of serum progesterone levels among treatment and control groups(F=4.306, P=0.014), the serum progesterone level in 1000mg/kg does group was lower than that of the control group (P<0.05), while there was no significant difference of serum progesterone between 250mg/kg or 500mg/kg groups and the control group (P>0.05).The levels of serum LH and FSH between trestment and cotrol groups didn’t change significantly(P>0.05); (5)The expression levels of P450arom mRNA in ovarian was statistically different in treatment and the control groups(H=15.895,P<0.05), compared with the control group, the expression levels of P450arom mRNA in ovarian increased in 250mg/kg,500mg/kg and 1000mg/kg does groups (P<0.01), while there were no significant differences of P450arom mRNA expression levels were observed among three treatment groups (P>0.05).The expression levels of P450scc mRNA in ovarian were significant different in treatment and the control groups(H=15.591 P<0.01), compared with the control group, the expression levels of P450scc mRNA in ovarian reduced in three treatment groups (P<0.01), but there were not significant differences in expression levels of P450scc mRNA among three treatment groups(P> 0.05); (6) The expression levels of PPARy mRNA in ovarian in 500mg/kg and 1000mg/kg does groups were significantly higher than that in the control group (P<0.05 and P<0.01), and the expression level of PPARy mRNA in 1000mg/kg does group was higher than those of 250mg/kg and 500mg/kg groups (P<0.05).Conclusion:(1) DBP has adverse effects on reproductive endocrine function of puberty female rats. The disrupting effects of DBP on reproductive endocrine functions of puberty female rats include:prolonged estrous cycle, increased the serum estradiol level and decreased serum progesterone level.(2)The possible mechanisms of female reproductive toxicity induced by DBP may be related to the increased expression of the key enzyme P450arom mRNA and the decreased expression of P450scc mRNA in ovary. The reproductive toxicity in puberty female rats of DBP may also be associated with the activating PPARy mRNA expression of granulosa cells in ovary.更多还原