Correlation Between sPLA₂-llA and Phosgene-Induced Rat Acute Lung Injury

Abstract

Secreted phospholipase A₂ of group IIA (sPLA₂-IIA) has been involved in a variety of inflammatory diseases, including acute lung injury. However, the specific role of sPLA₂-IIA in phosgene-induced acute lung injury remains unidentified. The aim of the present study was to investigate the correlation between sPLA₂-IIA activity and the severity of phosgene-induced acute lung injury. Adult male rats were randomly exposed to either normal room air (control group) or a concentration of 400 ppm phosgene (phosgene-exposed group) for there are 5 phosgene-exposed groups altogether. For the time points of 1, 3, 6, 12 and 24 h post-exposure, one phosgene-exposed group was sacrificed at each time point. The severity of acute lung injury was assessed by Pa_O2/F_IO2 ratio, wet-to-dry lung-weight ratio, and bronchoalveolar lavage (BAL) fluid protein concentration. sPLA₂-IIA activity in BAL fluid markedly increased between 1 h and 12 h after phosgene exposure, and reached its highest level at 6 h. Moreover, the trend of this elevation correlated well with the severity of lung injury. These results indicate that sPLA₂-IIA probably participates in phosgene-induced acute lung injury.

ACKNOWLEDGMENTS

We are deeply grateful to Prof L. Touqui for the generous gift of fluorescent phospholipid substrate and for technical assistance with the experiment in the measurement of sPLA₂-IIA activity.