The Effects of Pretreatment with Ambroxol on Airway Inflammation in Rats with Chronic Bronchitis Induced by Smoking

Objective To explore the role of intercelluar adhesion molecule-1(ICAM-1) on airway inflammation in rats with chronic bronchitis induced by smoking and study the effect of pretreatment with ambroxol and possible mechanism. Methods Male Wistar rats were randomly divided into three groups:the control group,smoking group,ambroxol intervention group. The rat model of chronic bronchitis was established by smoking only. For ambroxol intervention group,rats were pretreated with ambroxol through peritoneal injection at 35 mg·kg-1·d-1 for 75 days,six days each week. The histopathologic changes in hemotoxylin and eosin (HE) stained bronchopulmonary tissues were observed under optical microscope; total cell counts and differential analysis were performed in bronchoalveolar lavage fluid (BALF); the expression of ICAM-1 was detected by immunohistochemistry. Results The pathological change of model group was in consistent with that of human chronic bronchitis. The expression of ICAM-1 on bronchi and alveolar epithelial and bronchopulmonary capillary endothelial cells were positively correlated with the leukocyte numbers and neutrophil in BALF in the model group (P0.01). The expression of ICAM-1 in the model group significantly increased as compared with the control group(P0.01); which significantly decreased in ambroxol intervention group compared with the model group(P0.01). Conclusion ICAM-1 may be involved in the process of airway inflammation in rats with chronic bronchitis induced by smoking; ambroxol might have some effects on ameliorating airway inflammation by down-regulating the expression of ICAM-1 and inhibiting the aggregation of neutrophil.