In situ expression of ICAM-1 and its mRNA in the lung tissue of asthmatic rats.

In situ expression of ICAM-1 and ICAM-1 mRNA on the lung tissue of asthmatic rats was studied by immunohistochemical staining and in situ hybridization, respectively. The results showed that in normal rats ICAM-1 expression was rare on the endothelium of pulmonary artery and vein, and on the bronchial and alveolar epithelium. The distribution of ICAM-1 expression on the different part of lung tissue of asthmatic rats was similar to that of normal rats, but the level of ICAM-1 expression was significantly increased on the endothelium of pulmonary artery (EPA) and vein (EPV), bronchial epithelium (BEP) and alveolar epithelium (AEP) compared with those of normal and sensitized controls. The distribution and expression of ICAM-1 mRNA on the different part of lung tissue of normal and asthmatic rats were similar to that of ICAM-1 expression. In asthmatic rats, the expression of ICAM-1 mRNA on AEP and EPV was increased significantly compared with those of normal and sensitized controls. It is concluded that the increase of ICAM-1 expression on endothelium of pulmonary vessels, epithelium of broncheoli and alveoli may play an important role of inflammatory cell infiltration in asthmatic rats, and the increased expression of ICAM-1 in asthmatic rats was caused by the increase of expression of ICAM-1 mRNA.