Study On The Effect Of Soybean Isoflavones On Ovary Development In Ablactated Mice

ObjectiveThe purpose was to study the effects of SIF on the ovarian development andfunction of the ablactated mice.The data were to offer an important reference for thefurther research and the machanisms of female toxicity.MethodsIn the short-term exposure test1,The female mice were divided randomly into the4groups on postnatalday（PND）21.Mice in different treatment groups were exposured0,50,100and200mg/kg.bw of SIF from PND21to35by gavage. In addition,the weight of themice and the state of vagina opening was observed.After treatment, the indicatorssuch as serum E₂and P₄, pathological change of ovary,the ultra structure of ovariantissue use of transmission electron microscopy, apoptotic cells, and ovarian tissuelevels of Caspase3, Caspase8and Caspase9mRNA expression were detected.2,After exposured to SIF, tested female mice were superly ovulated byintraperitoneal injections of PMSG and HCG48h apart. Then females were matedwith normal male mice （ICR） overnight （two females per one male）. The indicatorssuch as rate of fertilization,number of zygotes,form of zygote were examined.In the subchronic test1,The female mice were divided randomly into the3groups on postnatalday（PND）21. The first group received distilled water by gavage（10ml/kg/d） fromPND21to56.The second group were exposured to200mg/kg.bw from PND21to35,then received distilled water from PND35to56. The third group were exposuredto200mg／kg.bw from PND21to56. In addition,the weight of the mice and thestate of vagina opening was observed.After treatment, the indicators such as serumE₂and P₄, pathological change of ovary,the ultra structure of ovarian tissue use oftransmission electron microscopy, apoptotic cells, and ovarian tissue levels of Caspase3, Caspase8and Caspase9mRNA expression were detected.2,After exposured to SIF, tested female mice were superly ovulated byintraperitoneal injections of PMSG and HCG48h apart. And then females weremated with normal male mice （ICR） overnight （two females per one male）. Theindicators such as rate of fertilization,number of zygotes,form of zygote wereexamined.ResultsIn the short-term exposure test1,There were no significant differences on body weight of mice among4groups（P>0.05）.2,Compared with control group，the ratios of the vagina opening of the highgroup was significantly higher（P<0.05）.3,The E₂and P₄level in the200mg/kg group were significantly higher thancontrol （P<0.05）.4,Compared to the control,the consitituent rate of the growth follicle number andthe mature follicle number on ovary increased significantly in the200mg/kggroup（P<0.05）.5,Apoptotic cells were visible in all groups; There were no significantlydifferences on the apoptotic rate of the granulose cell among4groups（P>0.05）.6,Caspase3and Caspase9mRNA expression significantly lower than that of thecontrol group （p<0.05）. There were no significantly differences on Caspase-8mRNAexpression among4groups （P>0.05）.7,There were no significantly differences on rate of fertilization among4groups（P>0.05）.The number of zygote were significantly got more by SIF（p<0.05）.In the subchronic test1,There were no significant differences on body weight of mice among4groups（P>0.05）.2,The age of the vagina opening of the third and the second group weresignificantly earlier than control group（p<0.05）.3,The E₂level in the third group were significantly lower than the control. There were no significant differences on E₂level between control and the second group（P>0.05）. There were no significant differences on P₄level among3groups （P>0.05）.4,There were no significant differences on the consitituent rate of the growthfollicle number on ovary among3groups （P>0.05）.5,Apoptotic cells were visible in all groups; compared with the control group, anincreased heterochromatin, chromatin margination, apoptotic bodies, mitochondrialedema, matrix thinning, and a decreased electron density in the third group. Weobserved that the apoptotic rate of the granulose cell in the atresic follicle increasedsignificantly in the third group compared to the control.6,Caspase-9mRNA expression significantly higher than that of the control group（p<0.05）. There were no significantly differences on Caspase3and Caspase8mRNAexpression among3groups （P>0.05）.7,There were no significantly differences on rate of fertilization among3groups（P>0.05）.The number of zygote were significantly got fewer by SIF（p<0.05）.Conclusions1, When female mice after weaning exposured to SIF for a short time,it couldaffect on ovary development as strogen,then promote the development of the ovary sothat the vagina opening of the mice was earlier, the consitituent rate of primordialfollicle,atresic follicle,mature follicle number was in disorder, the level of serum E₂was increased and the number of zygotes were increased. If the tested female micestop exposure to SIF,We could not find any abnormal on ovarian function and formin the short time.2, If exposured to SIF up to postpuberty, SIF could affect on ovary developmentas antiestrogen so that the level of E₂in serum was decreased, the apoptotic rate ofthe granulose cell in the atresic follicle was increased,and the number of zygoteswere decreased.