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Objective:Study on the expression and signification of N-cadherin、bFGF、PCNA on the neuroepithelium in golden hamster with neural tube defects model induced by hyperthermia.Methods:The pregnant golden hamsters were randomly divided into the experimental group with 30 and the control group with 25. At 3:30 pm on the 8th day of pregnancy, the experimental group were put into 42 degree temperature bath with 20min, meanwhile, the control group were put into 37 degree temperature bath with 20min. The experimental group with 10 and the control group with 10 were sacrificed on the 15th day of pregnancy, then the fetuses were got, to indentify the number of live and dead implantation、the embryo with absorption and teratism. Other pregnant rats with 35 were sacrificed at 2,8, 16,24,48hours after water-bath processing, then the fetuses were got, The fetuses were formalin-fixed, paraffin-embedded and cut continuously. The expression of N-cadherin, bFGF, PCNA on neuroepithelial cells of both experimental and control group were detected with immunohistochemical technique and image analyzer.Results:①The incidence rate of NTDs in experimental group was 70.91%, in comparison, the control group is zero, the difference is obvious.②The immunohistochemistry results of N-cadherin:at 2-8 hours after water-bath processing, N-cadherin positive cells are present in both the experimental group and the control group, the difference of OD value is insignificant statistically, there is also positive reaction in the internal and external membrane, notochord as well as around mesenchymal cells. After 16-24 hours exposure, the level of N-cadherin in the control group is strong positive, and yet it is weak positive in the experimental groups (p<0.01), there is no significant change in surrounding tissues. After 48 hours, N-cadherin positive reaction is no difference statistically in the experimental group compared with control group, the expression of N-cadherin has already decreased in the neural tube in both two groups.③The immunohistochemistry results of bFGF:At 2,8 and 16 hours after water-bath processing, the expression of bFGF on the neuroepithelium is positive, the difference is indistinct between the control group and experimental group. Compared with the control group, the value of optical delnsity of bFGF is significantly lower in the experimental group at the 24h and 48h after dispose (p<0.05), there is not obvious change in the internal and external membrane, notochord as well as Around mesenchymal cells. The expression of bFGF has gradually increased accompanied by gestational age in both experimental and control groups, there is still positive reaction in the internal and external membrane notochord as well as Around mesenchymal cells.④The immunohistochemistry results of PCNA:On the 8th day of pregnancy, the expression of PCNA is widespread in the neural tube tissue, the positive reaction is strong on the neuroepithelium, neural crest cells and around mesenchymal cells. After 2 and 8 hours exposure, the amount of PCNA positive cells on the nerviduct in the experiment group are less than the control group, but the difference is no significance statistically. Compare with the control group, the content of PCNA of epithelial cells in the experimental groups has already reduced significantly afterl 6,24 and 48 hours (p<0.05). After 24 hours exposure, the expression of PCNA has gradually decreased accompanied by gestational age in both experimental and control groups.Conclusion:Hyperthermia can decrease the expression of N-cadherin, bFGF, PCNA on the neuroepithelium; intervene in the recognition and adhesion among cells;disturb the balance of between proliferation and apoptosis, induce the neural tube defects, which might be one of the important ways on neural tube defects induced by hyperthermia.
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