Effects Of Folate During Pregnancy Of Rats On The Expression Of PCNA、P16、CyclinD1and The Fuction In The Placenta

Objective：The placenta is a special organ, It is related with the fetal whether isnormal or disease. The purpose of our study is to explore the effects of folateduring pregnancy of rats on the expression of PCNA、P16、CyclinD1and thelevel of FE₃in the placenta, so as to provide theoretical foundation and thedependent of exerperiment in clinical suppling folic acid.Methods:1Experimental animals and factors:40SD female rats were randomlydivided into control group and the experimental groups supplied by folate. Themodel of pregnant rats were made and divided into four groups,10rats in eachgroup.They eat and drink randomly, The rats of the experimental groups weresupplied by folate with different doses of2mg/kg/d、1mg/kg/d、0.5mg/kg/dbody weight. Control rats received only saline.2Obtained samples: The pregnant rats were killed on the13.5th day ofgestation respectively（E13.5d）, and their placentas and blood were taken out.tissue samples were embedded in Bouin.The blood would be put intoultracentrifuge.3Histological technique: The morphology and structures of rat placentasin control group and the experimental groups supplied by folate wereobserved by level of microscopy.4Immunohistochemical technique: It was used to observe the expressionof PCNA, P16and CyclinD1in placental tissue.5Enzyme-linked immunosorbent assay（ELISA）: Four groups weredetected for serum free estriol（FE₃） respectively on the13.5th day of gestationrespectivel by enzyme-linked immunosorbent assay.6The statistical analysis was performed with one-way analysis of variance （ANOVA） and q test.P<0.05was considered statistically significant.Results:1The result of microhistologyThere are no remarkable diffirences on the structure of rat placenta incontrol group and the experimental groups supplied by folate by level ofmicroscopy.2The result of Immunohistochemistry staining2.1The expression of PCNAThere are the expression of PCNA in each group.The expression ofPCNA in study groups supplied by folate are significantly higher thancontrol group in the placenta（P＜0.01）.Compared with the groups withfolate,the expression of PCNA in study groups supplied by folate withdifferent doses of2mg/kg/d、1mg/kg/d body weight are significantly higherthan0.5mg/kg/d body weight group in the placenta（P＜0.05）. There are noremarkable differences between the groups supplied by folate with a dose of2mg/kg/d and1mg/kg/d body weight（P＞0.05）.2.2The expression of P16There are the expression of P16in each group. The expression of P16instudy groups supplied by folate were significantly lower than control group inthe placenta（P＜0.01）.The expression of P16in study groups supplied byfolate with different doses of2mg/kg/d、1mg/kg/d body weight aresignificantly lower than0.5mg/kg/d body weight group in the placenta（P＜0.05）. There are no remarkable differences between the groups supplied byfolate with a dose of2mg/kg/d and1mg/kg/d body weight（P＞0.05）.2.3The expression of CyclinD1There are the expression of CyclinD1in each group. The expression ofCyclinD1in study groups supplied by folate are significantly higher thancontrol group in the placenta（P＜0.01）.The expression of CyclinD1in studygroups supplied by folate with different doses of2mg/kg/d、1mg/kg/d bodyweight are significantly higher than0.5mg/kg/d body weight group in theplacenta（P＜0.05）.There are no remarkable differences between the groups supplied by folate with a dose of2mg/kg/d and1mg/kg/d body weight（P＞0.05）.3The level of FE₃in pregnant ratsThe level of FE₃are higher and higher in control group、0.5mg/kg/d、1mg/kg/d、2mg/kg/d body weight. The level of FE₃in the groups supplied byfolate are significantly higher than control group（P＜0.05）. The level of FE₃in study groups supplied by folate with different doses of2mg/kg/d、1mg/kg/dbody weight are both significantly higher than0.5mg/kg/d body weightgroup（P＜0.05）. There are no remarkable differences between the groupssupplied by folate with a dose of2mg/kg/d and1mg/kg/d body weight（P＞0.05）.Conclusion:1There are no remarkable diffirences on the morphology and structure ofrat placenta in the groups supplied by folate compared with control group.2Folate can make the expression of PCNA higher. Folate may increasecell proliferation in some degree, cell proliferation is related with differentdoses supplied by folate.3Folate can make the expression of P16lower. The level of P16isrelated with different doses supplied by folate.4Folate may increase the level of serum FE₃in the pregnant rats, thelevel of serum FE₃is related with different folate doses.5We conclude that folate could help the development of the placenta andfunction in some degree during gestation.