Dexamethasone fails to improve bleomycin ‐induced acute lung injury in mice

Our data indicates that the inability of dexamethasone to improve the resolution of bleomycin outcomes, in particular, mortality rates, neutrophil infiltration and lung edema, may be due to the remaining alveolar damage observed at day 7 and repair impairment induced by dexamethasone. AbstractAcute respiratory distress syndrome (ARDS) features an exudative phase characterized by alveolar damage, lung edema and exacerbated inflammatory response. Given their anti ‐inflammatory properties, the potential therapeutic effect of corticosteroids has been evaluated in ARDS clinical trials and experimental models of ALI. These studies produced contradictory results. Therefore, our aim was to investigate the effects of dexamethasone in an animal model of bleomycin‐ induced acute lung injury and then to determine if the lack of response could be related to an impairment in repair ability of alveolar epithelial cells after injury. NMRI mice were challenged with bleomycin and then treated daily with dexamethasone or saline. Bronchoalveolar lavages (BAL) and lungs were collected for assessment of the inflammatory response and wet/dry ratio (lung edema) and for histological analyses. The effect of bleomycin and dexamethasone on wound repair was also evaluated in vitro on primary alveolar epithelial cell (ATII) cultures. Our data first showed that dexamethason e treatment did not reduce the weight loss or mortality rates induced by bleomycin. Although the TNF‐α level in BAL of bleomyci...
Source: Physiological Reports - Category: Physiology Authors: Tags: Original Research Source Type: research