IN-SITU EXPRESSION OF ICAM-1 AND ITS MESSENGER-RNA IN THE LUNG-TISSUEOF ASTHMATIC RATS

In situ expression of ICAM-1 and ICAM-1 mRNA on the lung tissue of ast hmatic rats was studied by immunohistochemical staining and in situ hy bridization, 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 IC AM-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 expressio n was significantly increased on the endothelium of pulmonary artery ( EPA) and vein (EPV), bronchial epithelium (BEP) and alveolar epitheliu m (AEP) compared with those of normal and sensitized controls. The dis tribution 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 exp ression. In asthmatic rats, the expression of ICAM-1 mRNA on AEP and E PV was increased significantly compared with those of normal and sensi tized controls. It is concluded that the increase of ICAM-1 expression on endothelium of pulmonary vessels, epithelium of broncheoli and alv eoli may play an important role of inflammatory cell infiltration in a sthmatic rats, and the increased expression of ICAM-1 in asthmatic rat s was caused by the increase of expression of ICAM-1 mRNA.