产前使用地塞米松影响坏死性小肠结肠炎新生鼠Toll样受体4表达的初步研究

发布时间：2018-04-15 13:25

本文选题：产前给药 + 地塞米松　；参考：《重庆医科大学》2012年硕士论文

【摘要】：目的：探讨产前使用地塞米松对新生SD大鼠小肠发育及肠道Toll样受体4（Toll-likereceptor4，TLR4）表达的影响。方法：12只成年SD孕鼠随机分为正常对照组、产前地塞米松干预组（dexamethasone，DEX组）、产前生理盐水干预组（normalsaline,NS组）三组，每组4只，于孕16、17、18天时，DEX组孕鼠肌肉注射地塞米松(0.5mg/(kg·d))，NS组孕鼠肌肉注射生理盐水(0.3ml/d)。正常对照组不予处理。各组孕鼠自然分娩（n=22天）。于第1、3、5天时处死各组新生鼠，称量小肠重量及长度；取近回盲部肠组织做病理切片，采用HE染色观察测量肠绒毛高度，免疫组化法检测TLR4蛋白表达；其余小肠部分荧光实时定量PCR法检测其TLR4mRNA的表达。结果：（1）各组新生大鼠随鼠龄增加，小肠长度逐渐增长，小肠重量逐渐增重，肠绒毛高度逐渐增高，小肠TLR4蛋白和mRNA表达逐渐减少。（2）1、3日龄时，DEX组新生鼠小肠长度及重量显著高于正常对照组及NS组(P0.05)，（3）1、3、5日龄时，DEX组小肠绒毛高度显著高于其他两组(P0.05)，DEX组新生鼠小肠TLR4蛋白和mRNA表达显著低于其他两组(P0.05)。（4）正常对照组与NS组比较，各时间点小肠长度与重量、肠绒毛高度及肠道TLR4表达无显著性差异(P＞0.05)。结论：产前地塞米松的使用可促进新生鼠早期小肠长度与重量的增长，增加肠绒毛高度，促进小肠形态发育成熟；产前地塞米松使用可减少新生鼠肠道TLR4的表达。目的：观察产前地塞米松(dexamethasone,DEX)使用对新生大鼠坏死性小肠结肠炎（necrotizingenterocolitis，NEC）发生率及肠道Toll样受体4（Toll-likereceptor4，TLR4）表达的影响，探讨其对NEC的保护作用及可能的机制。方法：实验分为正常对照组、产前地塞米松干预组（DEX组）、产前生理盐水干预组（normalsaline,NS组）三组，于孕16、17、18天时DEX组孕鼠肌肉注射DEX(0.5mg/(kg·d))，NS组注射NS(0.3ml/d)。DEX组及NS组所生新生鼠建立NEC动物模型。正常对照组不予处理。全部新生鼠于第5日处死，取近回盲部肠组织做病理切片，采用HE染色观察病理变化并做评分；免疫组化法检测各组TLR4蛋白的表达；其余小肠部分荧光实时定量PCR法检测TLR4mRNA的表达。结果：与NS组相比，DEX组新生鼠NEC发生率明显降低（P0.001)。正常对照组未出现NEC症状，NS组新生鼠出现典型的NEC症状，DEX组NEC症状比NS组出现得更晚、更轻；与正常对照组相比，DEX组和NS组肠组织病理学评分及TLR4表达显著增高（P0.05)；与NS组相比，，DEX组肠组织病理学评分及TLR4表达显著降低(P0.05)。结论：产前使用DEX对NEC大鼠具有保护作用，其机制可能是通过降低TLR4的表达从而发挥抗炎效应。
[Abstract]:Aim: to investigate the effects of prenatal administration of dexamethasone on small intestine development and expression of Toll like receptor 4 Toll-like receptor 4 (TLR4) in neonatal SD rats.Methods Twelve adult SD pregnant rats were randomly divided into normal control group, dexamethasone DEX group and normal saline intervention group (n = 4 in each group).The pregnant rats in DEX group were intramuscularly injected with dexamethasone (0.5 mg / kg / kg) on the 18th day of gestation. The pregnant rats in NS group were intramuscularly injected with normal saline (0.3 ml / d).The normal control group was not treated.The pregnant rats in each group were given natural delivery for 22 days.The neonate rats were killed at the 3rd day of the first week to weigh the weight and length of the small intestine, the proximal ileocecal intestinal tissue was taken as pathological sections, the villi height was observed by HE staining, and the expression of TLR4 protein was detected by immunohistochemical method.The expression of TLR4mRNA in other small intestine was detected by real-time quantitative PCR.Results (1) the length of small intestine, the weight of small intestine and the height of villi increased with the age of rats.The expression of TLR4 protein and mRNA in the small intestine gradually decreased. The length and weight of small intestine in the DEX group were significantly higher than those in the normal control group and NS group at the age of 5 days. The villus height of the small intestine in the DEX group was significantly higher than that in the other two groups.The expression of white and mRNA was significantly lower than that of the other two groups.There was no significant difference in intestinal length and weight, villus height and intestinal TLR4 expression at different time points (P > 0.05).Conclusion: the use of prenatal dexamethasone can increase the length and weight of small intestine, increase the height of villi and promote the maturation of small intestine, and the use of prenatal dexamethasone can reduce the expression of TLR4 in intestine of newborn rats.Objective: to observe the effect of dexamethasone (DEX) on the incidence of necrotizing enterocolitis (NECs) and the expression of Toll-like receptor 4 (TLR4) in neonatal rats with necrotizing enterocolitis.Methods: the experiment was divided into normal control group, prenatal dexamethasone intervention group (DEX group), prenatal normal saline intervention group (NS group) three groups. At the 18th day of gestation, the pregnant rats of DEX group were injected intramuscularly with NS(0.3ml/d).DEX group and NS group to establish NEC animal model.The normal control group was not treated.All the neonate rats were killed on the 5th day. The intestinal tissues of proximal ileocecum were taken as pathological sections. The pathological changes were observed by HE staining and the expression of TLR4 protein in each group was detected by immunohistochemical method.The expression of TLR4mRNA in other small intestine was detected by real-time quantitative PCR.Results: compared with NS group, the incidence of NEC in DEX group was significantly lower than that in NS group (P 0.001).No NEC symptoms were found in the normal control group. The typical NEC symptoms were found in the newborn rats of NS group. The NEC symptoms in DEX group were later and lighter than those in NS group.Compared with the normal control group, the intestinal histopathological score and TLR4 expression in the DEX group and NS group were significantly higher than those in the NS group, and the intestinal histopathological score and TLR4 expression in the DEX group were significantly lower than those in the NS group.Conclusion: prenatal use of DEX has protective effect on NEC rats, and its mechanism may be to play an anti-inflammatory effect by reducing the expression of TLR4.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R722.1

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