Correlation of lung compliance and quantities of surfactant phospholipids after acute alveolar injury from N-nitroso-N-methylurethane in the dog.

Acute alveolar injury was induced in dogs by subcutaneous injection of 8 mg of N-nitroso-N-methylurethane per kg of body weight. Two to seven days after the injections, the change in respiratory compliance was measured, alveolar and lung tissue disaturated phosphatidyl choline (DSPC) were quantified, and fatty acid patterns of alveolar phosphatidyl choline were determined. Progressive decreases occurred in respiratory compliance and in alveolar and tissue DSPC. Mean alveolar DSPC decreases occurred in respiratory compliance and in alveolar and tissue DSPC. Mean alveolar DSPC decreased to 22% (p less than 0.001) of that of the control study and significant linear correlation (p = 0.02) between respiratory compliance and alveolar DSPC quantity was found. Mean tissue DSPC decreased to 60% of that of the control study (p less than 0.001) and reductions in alveolar and in type II cell DSPC were estimated to be nearly equivalent. The proportion of palmitate in lavage phosphatidyl choline was increased by a mean of 9%. These studies demonstrated a decrease in surfactant lipids correlated with decreased compliances in acute alveolar injury and suggested that qualitative and quantitative changes in surfactant result from injury to alveolar type II cells.