Recombinant plasma gelsolin diminishes the acute inflammatory response to hyperoxia in mice

Background: The acute respiratory distress syndrome remains a common and poorly understood complication of a variety of insults. Ventilation with high concentrations of inspired oxygen may further damage already compromised lungs. By scavenging extracellular actin and modulating the effects of lysophosphatidic acid, plasma gelsolin could serve a critical protective role against oxidant injury. Methods: Mice exposed to <95% O-2 for a total of 72 hours were treated with gelsolin or albumin after 24 and 48 hours. Results: Neutrophil counts in bronchoalveolar fluid rose (P=0.0002) and gelsolin levels dropped (P<0.00001) in mice with acute hyperoxic lung injury. The acute inflammatory response to hyperoxia was significantly reduced in the gelsolin- compared with the bovine serum albumin-treated mice (P=0.03). Conclusions: These data imply that i) gelsolin depletion contributes to the pathogenesis of oxygen toxicity and ii) repletion of gelsolin can partially abrogate the resultant exudative response.