| objective:To establish the rat chronic bronchitis model bypassive cigarette smoking plus intratracheal instillation oflipopolysacchride(LPS),to observe the changes of pathology in airway andlung tissue and the expression of early growth response-1(EGR-1), plateletderived growth factor-BB(PDGF-BB)during different period, to research theantiinflammatory effects of inhaled Pulmicort Respules on themodel.Methods:40 Wistar rats(weight 200±20g)were randomly divided into8 groups,and they were breed as the same conditiong.(1)Healthy control group(n=15):They were breed without paticular process,and were killed respectivelyon the 7th,14th,and the 28th day. (2)Model group:The whole process was 28days.200μg lipopolysaccharide(LPS) (200μg/200μl)was instilledintratracheally on the first day and the 14th day. and the rats were exposured tocigarette smoke , 0.5h / d for four weeks . Model group1W(n=5),2W(n=5),4W(n=5)were killed respectively on the 7th,14th,and the28th day. (3)Drug inhalation group(n=5): After the 28 days of modelestablishing, rats received inhalation of Pulmicort Respules since the 29thday,20min/d for two weeks. (4) Inhalation control group(n=5): After the 28days of model establishing,the rats were breed for two weeks.After the ratswere killed,The pathologic changes of airway and lung tissues were observed.Bronchial wall and gland / bronchial wall of the rats were measured.Thenimmunohistochemical stains were performed with EGR-1 polyclonal antibodyand PDGF-BB monoclonal antibody. The expressions were quantitativelyanalyzed in the bronchia and lung tissue.Results:the bronchial and lung tissueof model group 1W,2W,4W have chronic bronchitis changes in differentdegree.The healthy control groups have barely changes. The model group 4Wrats shared specific pathological features in trachea bronchi and lung tissue withthat of human chronic bronchitis and obstructive emphesema.Bronchial walland gland / bronchial wall of the model groups were significantly higher thancorresponding control group(p<0.01). Rats of drug inhalation group were notdictinctly different to inhalation control group rats in pathological changes.bronchial wall and gland / bronchial wall of the drug inhalation group werenot significantly different to inhalation control group(p>0.05). Strong positivestain of PDGF-BB and EGR-1 protein was found in the interstitial conncetivetissue,the bronchial wall and the wall of blood vessels in the bronchial andlung tissue from the model group.The integral optical density of EGR-1 andPDGF-BB was significantly different in Model group 1W ﹑ 2W ﹑ 4W(F=463.101,268.279,p<0.01),and both were different in drug inhalationgroup and inhalation control group(p<0.01). The expression of EGR-1 waspositive correlated with that of PDGF-BB(r=0.987,p<0.01).Conclusion: (1)In the progress of establishing rat's chronic bronchitis model by passivecigarette smoking plus intratracheal instillation of LPS,the pathologic changesof bronchia and lung tissues increasingly progressed,till the typical changes ofchronic bronchitis and obstructive emphesema were observed.It showed thatchronic bronchitis model can be successfully established by passive cigarettesmoking plus intratracheal instillation of LPS once more.(2)EGR-1 andPDGF-BB contributed to the process of inflammation of chronic bronchiti.(3)EGR-1 and PDGF-BB were positive correlated with each other,and wespeculate that they can induce each other,while in different way in differentconditions.(4)Inhaled Pulmicort Respules for two weeks could notsignificantly change pathology in airway and lung tissue of the rats of chronicbronchitis model,but it could obviously reduce the expession of EGR-1 andPDGF-BB of them.We speculate that instillation of hormone for two weeks canrestrain the expression of inflammation factor,but it is too short to change thepathology.
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