| Objective:To examine the effects of inhaling vitamin A and budesonide on controlling airway inflammation and the expression of thymic stromal lymphopoietin in lung tissue of difficult asthma rats.Methods:48cases female grown SD rats were sensitized and challenged with chronically inhaling ovabumin(OVA) for 4 weeks to establish difficult asthma models.Then they were divided into 3 groups randomizedly.There were 16 cases in asthma group,budesonide group and vitamin A group respectively.Budesonide group inhaled 0.02%budesonide for 3 times,each time 30 minutes,once every other day;Vitamin A group inhaled 1250IU/ml vitamin A suspl for 3 times,each time 30 minutes,once every other day;Asthma group inhaled 90%ethanol for 3 times,each time 30 minutes,once every other day.Half of rats of each group were killed after excitated by OVA 4 weeks and 5 weeks.The expression of TSLP on rats lung tissue was detected with western-blotting and fluorescent-immunohistochemistry;and the lung tissues of rats were stained with HE anf PAS method.Results:(1)Histopathological changes:Airway spaces stenosised,airway mucous membranes thicken and many inflammatory,cells(such as eosinophils, lymphocytes)infiltrated in the stroma of airway and many goblet cells were found in the asthma group rats'lung tissue,and lymphocytes of spleen white pulp were moderately proliferating;the airway inflammatory reaction were alleviated in upper-killed rats of asthma group.The vitamin A group rats' airway inflammatory reaction was more serious than asthma group in early phase,and lymphocytes of spleen white pulp were moderately proliferating;whereas it recovered significantly in last phase,and lymphocytes of spleen white pulp stopped proliferatating.Few epithelium of all bronchus mucosa were fall off and light lymphocytes infiltrated in the stroma of airway of the budesonide group rats,and lymphocytes of spleen white pulp were mildly proliferating;but airway inflammatory reaction were aggravated when rats stopped inhaling budesonide,and lymphocytes of spleen white pulp were moderately proliferating.(2)Western-blotting showed that the expression of TSLP in rats' lung tissue of Asthma group(3454.750±410.715,2985.250±278.534)was significantly higher than vitamin A group(3055.000±307.115,3016.500±342.573)and budesonide group(2658.375±254.289,2297.500±134.481)(p＜0.05) in early and last phase.The expression of TSLP in rats' lung tissue of vitamin A group was higher than budesonide group(p＜0.05).There was significant difference between early and last phase in asthma group and budesonide group(p＜0.05),but there was no significant difference between early and last phase in vitamin A group(p＞0.05).(3) Fluorescent-immunohistochemistry revealed that asthma group(39.875±4.224,35.375±3.926)(/1013505 um~2)rats' lung had the most TSLP positive cells among three groups in early and last phase.Vitamin A group(35.125±2.748,37.875±2.167)took second place and rats' lung positive cells were more than budesonide group(30.875±1.808,28.500±1.927)(P＜0.05).The asthma group and budesonide group rats' lung positive cells became less in last phase(P＜0.05),but it was opposite to vitamin A group(P＜0.05).Conclusion:(1) Inhaling vitamin A regulates difficult asthma rats'lung histopathological changes bidirectionally:in early phase vitamin A augments lymphocytes of spleen white pulp proliferatation and induces inflammatory corpuscle infiltrating in lung,but it lightens airway inflammation by abating lung goblet cells' infiltrating and renovating epithelium in last phase.(2) Difficult asthma rats attend by steroid-dependent commonly.Budesonide alleviates lung inflammatory reaction of difficult asthma rats,but there is end-of-dose failure.(3) Budesonide can lastingly depress expression of TSLP in lung tissue.Vitamin A plays a weaker role on expression of TSLP in lung tissue than budesonid.TSLP is significantly expressed in lung tissue of difficult asthma group rats,but there has not relativity between TSLP and severity of illness sometimes. |
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