Effect of Corticosteroids on Lung Volume-Pressure Curves in Bleomycin-Induced Lung Injury in the Rat

In this study we investigated changes in volume-pressure curves at various stages after bleomycin induced lung injury (6 h, and 3, 7, and 28 days) and tested the ability of steroids to influence these changes. The most significant decreases in volume-pressure curves were observed at 3 days post bleomycin, a time point that correlates to the peak period of inflammation. Steroids as drugs of high antiinflammatory potency were used in order to modulate the inflammatory response and possibly the volume-pressure curve changes observed during the natural course of bleomycin induced lung injury. Dexamethasone treatment significantly inhibited the decreases in volume pressure curves observed at 3 days post bleomycin, whereas methylprednisolone did not. Also both steroids significantly inhibited inflammation as measured by histological evaluation and the presence of cells in the bronchoalveolar lavage fluid.