Alveolar epithelial injury in vitro: temporal evolution and strain rate sensitivity

The onset of ventilator-induced lung injury (VILI) is linked to a number of possible mechanisms. To isolate the role alveolar epithelial deformation may play in the development of VILI, we have developed an in vitro system in which changes in alveolar epithelial cell viability can be measured after exposure to tightly controlled and physiologically relevant deformations. In this communication we explore the relative effect of deformation rate and duration on cell viability. Rat primary alveolar epithelial cells were exposed to a variety of cyclic biaxial stretch protocols, and deformation-induced injury was found to occur rapidly, with the majority of cell death occurring during the first five minutes of deformation. In addition, deformation-induced injury was found to be relatively insensitive to the rate of deformation