Dynamic Expression And Significance Of NF-κB And ICAM-1 In The Rats Of Bleomycin-induced Pulmonary Fibrosis.

Background: Interstitial lung disease consists more than 200 kinds of diseases .The pathologicfeatures of pulmonary fibrosis are characteristic of lung tissue stroma cells proliferation,extracellular matrix sedimentary, lung tissue reconstruction, and the clinical features areprogressive exertional dyspnea, diffuse infiltrating umbra in X-ray, restrictive ventilatorydisorder, diffusion functiong loss and hypoxemia. Their morbidity and mortality are differentand their severity are variable, but there is not specific healing. With the research of thepathogenesy of pulmonary fibrosis increasing ,many new thearapic methods appear topulmonary fibrosis. Therefore, it's very significant to enhance the research of thediscrimination , clinical diagnosis ,and therapy. NF-κB is a significant transcription factor,and ccommodates the expression of many cytokines , erzymes and intercellular adhesionmolecules. It is relevant with the patho-procedure inflammation. Here we establish theanimal model of pulmonary fibrosis to investigate the variation of NF-κB and ICAM-1 in theprocess of pulmonary fibrosis, so as to further explore the mechanism of pulmonary fibrosisand provide a new theoretical basis for the clinical treatment.Objective:1.To investigate the lung tissue pathological changes in the rats of pulmonaryfibrosis.2. Test the content of hydroxyproline in the lung tissue.3. Watch the changes of NF-κB and ICAM-1 in the lung tissue in rats of pulmonaryfibrosis.Methods:90 rats were randomly divided into the normal group(N-group,n=30),the modelgroup(M-group,n=30)and the dexamethasone group (D-group,n=30)．The pulmonary fibrosismodel was established by intratracheal injection of bleomycin with rats of the M-group andD-group；while rats of the N-group injected with distilled water．From the day on,rats of theD-group were injected with dexamethasone in intraperitonea1 every other day,those of theN-group and M-group were injected with saline．The animals were killed on the 1st,3rd,7th,14th,and 28th days after treatment,each six rats each group .Hold the lung tissue,stain it withHE and Masson,investigate the lung tissue pathological changes and assay the content ofhydroxyproline in them using the alkaline solution. Detect the contents of NF-κB and ICAM-1 inthe lung tissue by using the method of immunohistochemistry.Results:1.Pathological evidence of the M-group rats demonstrated that the alveolar compartmentcompanied with massive inflammatory cell invasion and a number of myofibroblast proliferationbecame more thick．However,lung injury in the D-group rats got better than that in theM-group．2.The content of hydroxyproline was increasing as time goes, and achieved peak on the 28th day both in M-group and D-group, but that of the M-group was significantly higher thanthat of the N-group(P < 0.05), and the D-group was significantly lower than the M-group (P <0.05).3.Immunohistochemistry results show: NF-κB in lung tissues in model-group showed ahighest expression scoring on the first day , and reduced on the 14th day, and still higher thanthat in N-group on the 28th day ; The expression scoring of NF-κB in D-group was smaller thanthat in M-group every time, and equal to the normal-group almost on the 28th day.ICAM-1 inlung tissues in model-group showed a highest expression scoring on the 7th day , and reduced onthe 14th day, and still higher than that in N-group on the 28th day ; The expression scoring ofNF-κB in D-group were smaller than that in M-group every time, but still higher than thanN-group on the 28th day.ConclusioConclusion The content of NF-κB and ICAM-1 were increasing in the stage of alveilitisobviously and decreasing significantly in the period of fibrosis. They show a regular pattern ofrising to the peak early and briefly in pulmonary fibrosis. It implies that they play an importantrole in the earlier period of pulmonary fibrosis.