Effects Of Glucocorticoid On Airway NGF And IGF - I Expression In Asthmatic Rats

Objective To study the relationshiop between nerve growth factor (NGF) and insulin-like growth factor-Ⅰ (IGF-Ⅰ) and the thickness of airway smooth muscle in asthmatic rats, and the role of early application of dexamethasone in the prevention and treatment of asthma.Methods30Wistar rats were randomly divided into control-group, asthma-model-group and hormonal-intervention-group. Rats needed inhale ovalbumin in a long term to make asthma models, the intervention group needed Intraperitoneal injection of dexamethasone (0.5mg/Kg) before each ovalbumin’ inhalation, and control-group used saline instead. Use Immunohistochemistry to test the expression of NGF and IGF-Ⅰ in the airway and make quantitative analysis. Measure the circumference and thickness of small airways, and observed the cell counts and classification of lavage fluid.Results Compared the control-group,the expression of NGF、IGF-Ⅰ the thickness of the bronchial smooth muscle cells(BSMC),and the number of the BSMC was significantly higher in the asthma-group and hormonal-intervention-group (F=60.19-284.63,*q=6.57-15.93,*P<0.05),the indexes in hormonal-intervention-group were lower than in asthma-group(#q=5.23～9.15,#P<0.05). Correlation analysis showed that NGF、IGF-Ⅰ in asthmatic group and smooth muscle thickness were positively correlated (r=0.473、0.819, p<0.05), also were positively correlated with BALF total cel、Lyms (r=0.603～0.783, P<0.01)Conclusion Early use of corticosteroids can reduce the expression of NGF and IGF-I in the airway, reduce remodeling of airway in asthma.