外源性肺表面活性物质与大鼠哮喘发作及表皮生长因子的变化(英文)

Influence of exogenous pulmonary surfactant on asthma attack and epidermal growth factor in rats

背景:有研究证实,外源性肺表面活性物质参与哮喘大鼠哮喘发作,并与表皮生长因子及其表皮生长因子mRNA的表达相关。目的:探讨肺表面活性物质对哮喘大鼠模型哮喘发作、表皮生长因子及表皮生长因子mRNA表达的影响。设计:以实验动物为研究对象的观察对比实验。单位:一所军医大学医院的呼吸内科。材料:实验于2004-04/2004-07在第四军医大学实验动物中心实验二室及病理学教研室免疫组化实验室完成。选择60只体质量为100～120g的雄性SD大鼠,由第四军医大学实验动物中心提供。随机分为3组,即正常对照组、哮喘对照组和肺表面活性物质治疗组,每组20只。方法:建立哮喘大鼠模型,哮喘对照组、肺表面活性物质治疗组腹腔注射免疫原液1mL及气管炎菌苗1mL腹腔注射致敏,正常对照组给予等体积生理盐水。致敏2周后,哮喘对照组、肺表面活性物质治疗组给予10g/L卵蛋白溶液,正常对照组给予理盐水超声雾化吸入20min激发,肺表面活性物质治疗组每次激发前给予氧气驱动雾化吸入肺表面活性物质100mg/kg。采用免疫组织化学的方法检测表皮生长因子的表达,用逆转录聚合酶链反应的方法检测表皮生长因子mRNA。主要观察指标:各组大鼠哮喘发作情况及其支气管肺组织中表皮生长因子及表皮生长因子mRNA的表达水平比较。

BACKGROUND:There are reports that exogenous pulmonary surfactant(PS) participating in acute asthma attacks in rats with asthma and has correlation with epidermal growth factor(EGF) and expression of EGFmRNA . OBJECTIVE:To observe the effect of PS on EGF and EGFmRNA in asthmatic rats. DESIGN:Controlled experimental study on experimental animals. SETTING:Respiratory departmentof a military medical university affiliated hospital. MATERIALS:The experiment was completed in Laboratory 2 of Experiment Animal Center; Immunohistochemistry Laboratory,Department of Pathology of Fourth Military Medical University of Chinese PLA from April 2004 to July 2004.Sixty male SD rats weighting 100-120 g were provided by the Experiment Animal Center of the Fourth Military Medical University of Chinese PLA.The animals were randomly divided into 3 groups,that is normal control group,asthma control group(asthma group) and PS treatment group(treatment group) with 20 rats in each group. METHODS:The models of asthmatic rats were established.1mL of immunogen stock suspension and 1 mL trachitis vaccine were injected intraperitoneally into the rats in the asthma group and treatment group respectively,and the normal control group were treated with the same volume of saline.Two weeks after being allergic,10 g/L oval bumin were given to the asthma group and treatment group.The normal control group was given saline ultrasonic nebulization for 20 minutes; the treatment group was performed atomizing inhalation PS 100 mg/kg driving by oxygen before each provocation.The expression of EGF was detected with immunohistochemistry and the expression of EGF mRNA was detected with reverse transcription-polymerase chain reaction(RT-PCR). MAIN OUTCOME MEASURES:The onset condition of the rats in each group and the comparison of the level of EGF and the expression of EGFmRNA in lung tissue of the bronchus. RUSULTS:There were 20 rats entered the result analysis in each group.Onset rate of asthma in asthma group[90%(18/20)]was higher than that in the treatment group[5%(1/20)](χ2=28.97,P< 0.01).The image analysis of the EGF expression showed that the absorbance in the asthma group(9.652±1.086)was higher than that in the normal control group(3.267±0.986)(t=18.552,P< 0.01).The absorbance in the treatment group(4.132±1.012) was similar to that in the control group(P >0.05); The electrophoresis bands of mRNA amplified products in each group showed that in the normal control group the expression was weak and it was strong in the asthma group.The expression in the treatment group was obviously weaker than that in the control group. CONCLUSION:Exogenous PS can reduce the onset of asthma and its mechanism might be related with inhibiting the synthesis and release of EGF.