【作者】 赵英姿；

【导师】 李菁华； 肖纯凌；

【作者基本信息】 吉林大学 ， 病原生物学， 2011， 硕士

【摘要】 目的本实验制备大鼠染尘染毒后的动物模型,分析大气混合污染物对大鼠血清和肺组织中SP-B表达的影响,研究大气混合污染物对大鼠呼吸道损伤的作用机制,为控制大气污染、制定防治对策提供理论依据。方法本研究在乙醚麻醉下,通过将实验组大鼠注入含有PM2.5的生理盐水混悬液和吸入含有SO2、NO2、CO的空气混合气来建立动物染尘染毒模型。应用ELISA法测定血清和BALF中肺表面活性蛋白B(Pulmonary surfactant protein B,SP-B)水平,免疫组化法测定SP-B在肺组织中的表达,实时荧光定量RT-PCR检测肺组织SP-BmRNA的表达。结果染毒1d组、7d组和30d组大鼠BALF和血清中SP-B的含量与各自对照组相比较无明显变化;大鼠肺组织在染毒7d组SP-BmRNA的表达高于对照组和染毒1d组和30d组(P<0.05);染毒1d组和7d组SP-B蛋白的含量明显低于对照组(P<0.01),染毒30d组SP-B蛋白的含量高于对照组(P<0.05),染毒1d组大鼠肺组织中SP-B的表达明显低于染毒7d和30d组(P<0.01)。结论1、大气混合污染物所致急性炎症反应中,大鼠血清及BALF中SP-B含量均无明显变化,提示SP-B作为一种疏水蛋白可能不是肺组织受损伤敏感生物指标。2、免疫组化方法显示,在大气混合污染物的早期炎症反应(1 d和7d),由于肺组织受损,肺组织内的SP-B含量低于对照组,而在30d时,肺组织内SP-B的含量升高,说明肺组织的代偿性保护作用。3、在染毒7d时,肺组织中SP-B mRNA的表达水平上调,代偿性地合成SP-B蛋白。4、SP-B mRNA水平变化可作为早期肺损伤的敏感性生物学指标。SP-B是肺部表面活性物质的重要组分之一,受损肺组织早期可出现肺组织SP-B及SP-BmRNA表达的变化,为临床肺组织疾病的防治提供理论指导。更多还原

【Abstract】 Air pollution is one of the primary risk factor in public heath. In recent years, it is known that particles less than or approximately 2.5μm in diameter (PM 2.5) are more hazardous than particles 2.5-10μm in diameter to public health. PM 2.5 may invade the bronchial, lung by inhalation, and reaches inside tissue of lung to form deposition. The long-term exposure of respiratory system to PM2.5 may give rise to bronchial inflammation. Alveolar type II epithelial cells play an important role in promoting adsorption of surface gas-liquid phospholipids, anti-infection and protection of lung tissue from damage. Some studies have showed that abnormal synthesis and metabolic of pulmonary surfactant protein B (SP-B) result in pulmonary disorder.Objective:To establish an animal model exposure to polluted dust, SP-B level in serum and lung tissue of animals is detected to provide theoretical basis of prevention and control of atmospheric pollution.Methods:78 Wistar rats (190-210g) were randomly divided into experimental groups and control groups ( experimental groups include group 1, 2, and 3,control groups include group 1, 2, and 3). Animals in experimental group are challenged with polluted dust (PM2.5) 1day, 7days and 30 days, respectively. Control rats are given to air. The SP-B levels both in pulmonary tissue and in serum are detected using immunohistochemical method, ELISA and RT-PCR.Results1. SP-B levels in BALF and in serum of rats The SP-B levels in BALF and in serum do not show significant differences between experimental group and control group (P>0.05), and there is no significant differences among the experimental groups (P>0.05).2. SP-B mRNA expression in pulmonary tissue of rats The expression levels of SP-B mRNA in experimental group 2(challenged with PM 2.5 for 7 days) is higher in comparison with in control group (P<0.01). There is no difference between experimental group 1 and group 2.3. SP-B levels in pulmonary tissue of rats SP-B levels in experimental group 3 (challenged with PM 2.5 for 30 days are higher than that in control group 3 (P<0.05), and SP-B levels in experimental group 1and 2 are lower than that in control group (P<0.01).Conclusion:1. In acute inflammation caused by air pollution, SP-B levels both in BALF and in serum exhibit no apparent changes. It is suggested that SP-B levels both in BALF and in serum can not serve as a indicator for pulmonary damage.2. Immunohistochemistry showed that SP-B levels in pulmonary tissue is lower in early inflammatory stage (1 day and 7 days) due to tissue damage.3. when animals were challenged with PM 2.5 for 7 days, the expression level of SP-B were up-regulated in comparison with control animals.4. SP-B mRNA expression may act as biological indicator of early pulmonary damage.更多还原