ALI and the Alveolar Epithelial Barrier

Until recently, the critical importance of the alveolar epithelial barrier in the pathogenesis of and recovery from severe acute lung injury had not been appreciated. However, progress in two areas has created a breakthrough in our under-standing of the importance of the alveolar epithelium in ARDS. First, in the past 10 years, the mechanisms that regulate transport of fluid and protein across the normal alveolar epithelial barrier have been identified. Second, there are now new data regarding the mechanisms responsible for injury to the lung epithelial barrier and on the process of alveolar epithelial cell repair. Therefore, it is now possible to study the resolution and recovery of lung injury in both the experimental and clinical settings.