The Expression Of ICAM-1 And E-Selectin Onbronchpulmonary Tissues Of A Rat Model Of Chronic Obstructive Pulmonary Disease

Objective: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, and its pathogenic mechanism has been completely unkown yet. Recent studies have shown that cell adhesion molecules(CAMs) involved in the progress of COPD. We had studied the exprese of intercellular adhesion molecule-1 (ICAM-1) and E-selectin on the bronchopulmonary tissues of a COPD rat model and observed the impact of ipratropium(Atrovent) on both above factors..Methods: COPD rat model was established by intratracheal instillation of lipopolysacharide(LPS) twice and exposure to cigarette smoke daily. 42 Wistar rats were randomly divided into 3 groups; (1)The healthy control group: no intervention was administered. (2) The COPD model group: given LPS (200μg/100μl/one) by intratracheal instillation at the first and fifteenth day, and exposured to cigaratte smoke (about 5% concentration) for half an hour in a close glass box(72L) daily. (3)The ipratropium group: were inhaled ipratropium (1mg/4ml) in a close glass box(36L) daily started at the eighth day of experiment. After 32 days, lung function test,bronchoalveolar lavage and pulmonary samples were performed. The COPD model was evaluated by changes in histopathology,lung function and total and differentialleukocyte counts in bronchoalveolar lavage fluid (BALF). The expression of ICAM-1 and E-selectin on rat lung tissue was detected by means of immunohistochemistry (SP).Results: (1)Esteblishment of COPD model: The microscopic pathologic changes of the model group were similar to those in COPD patients. The total leukocyte numbers and neutrophils in BALF were significantly increased in both model group and ipratropium group compared with the control group (P<0.05, totally). The total leukocyte numbers and neutrophils in BALF of the model and ipratropium groups were significantly increased compared to the control group (P<0.05,totally), the percentage of alveolar macrophage was significantly decreased compared to the control group (P<0.05), but the absolute number were more than those in the control group; The total and differential leukocyte counts in BALF of the ipratropium group wasn't significantly different compared to the model group (P>0.05, totally). inspiratory resistance (Ri) and expiratory resistance (Re) of the model and ipratropium groups were significantly increased compared to the control group (P<0.05, totally), and FEV0.3/FVC(forced expiratory volume in 0.3s/forced vital capacity) was significantly decreased compared to the control group (P<0.05, totally); Ri,Re and FEV0.3/FVC of the ipratropium group weren't significantly different compared to the model group. (2) Results of immunohistochemistry: The expression of ICAM-1 on bronchi and alveolar epithelial and bronchopulmonary capillary endothelial cells of the model and ipratropium groups was significantly increased compared to the control group (P<0.05, totally); The expression of ICAM-1 of the ipratropium group wasn't significantly different compared to the model group (P>0.05). The expression of E-selection on bronchpulmonary capillary endothelial cells of the model and ipratropium groups was significantly increased compared to the control group (P<0.05, totally); The expression of E-selectin of the ipratropium group wasn't significantly different compared to the model group (P>0.05). (3) correlation analysis: The expression of ICAM-1 on bronchpulmonary tissues was positively correlated with the leukocyte numbers and neutrophils in BALFin the model group (r=0.76, p<0.01; r=0.65,p<0.05, respectively); The expression of E-selectin on bronchpulmonary tissues was positively correlated with the leukocyte numbers and neutrophils in BALF in the model group (r=0.82,p<0.001;r=0.79,p<0.001 , respectively).Conclusion (1) COPD animal model can be established by intratracheal instillation of LPS and exposure to cigarette smoke. (2)ICAM-1,E-selectin may be relevant to the moving of leukocyte through endothelial and the recruitment of leukocyte into site of inflammation, and involve...