[Increase of surfactant and protein contents in the alveolar space after lung preservation]

This study is to describe the pathophysiological change in the alveolar space due to reperfusion injury in the lung. Six pigs, weighing 20-22 kg, were used. Through the left lateral thoracotomy, both sides of pulmonary artery (PA) and bronchus (Br) were exposed and occluded the left side of PA and Br. Left lung was perfused with 200 ml of UCLA Formula and preserved in room temperature (27 degrees C) for 3 hours. After the clamps were released, right side of PA and Br were clamped and pulmonary artery pressure (PAP) and static lung compliance were measured in ischemic lung. Then, animals were sacrificed and alveolar wash was performed. With the fluid taken from the alveolar wash, the surfactant and protein content in the alveolar space were measured using Malate's method and Lowry's method, respectively. As the results, PAP (mmHg) was significantly increased after the reperfusion, from 34.0 +/- 8.1, to 85.4 +/- 8.7 (p less than 0.001). Lung Compliance (ml/cmH2O) was decreased, from 0.52 +/- 0.07 to 0.31 +/- 0.1 after the reperfusion (p less than 0.001). The content of surfactant in the left lung described as a ratio (left/right) was 252.5 +/- 87.8% of that in right side. The content of protein in the left lung was 289.5 +/- 137% of that in right side. We concluded that both contents of surfactant and protein were increased in alveolar space after the reperfusion.