Emphysema induced by intravenously administered endotoxin in an alpha₁-antitrypsin-deficient rat model

The effect of repeated intravenous injections of Escherichia coli endotoxin on lung structure and lung parenchymal elastin proportions was studied in rats rendered deficient in alpha₁-antitrypsin by administration of galactosamine. Within 24 h after endotoxin administration, polymorphonuclear leukocyte sequestration was demonstrable by microscopy and differential cell counts of pulmonary lavage fluid. Measurement of the proportion of elastin in lung parenchyma at 24 h revealed values in the normal range; 10 wk after repeated galactosamine and endotoxin administration, there was a reduction in the proportion of lung parenchymal elastin. At 10 wk, these animals showed a significant increase in the mean linear intercept and pulmonary compliance. Animals treated with endotoxin alone developed some but not all of the changes seen in the animals deficient in alpha₁-antitrypsin.