Oxidant Effects on Rat and Human Lung Proteinase Inhibitors

This report describes a study by Dr. Johnson and colleagues to test the hypothesis that inhaled oxidants can cause lung damage by inactivating the proteinase inhibitors that normally protect the lung from proteolysis. In the first set of experiments, the functional activity of rat alpha-1-proteinase inhibitor (á1-PI) was measured in rat lung lavage fluid from rats exposed acutely or chronically to varying concentrations of NO₂, diesel exhaust, O₃, and O₃ in conjunction with CO₂. In the final set of experiments, functional activity of á1-PI was measured in the bronchoalveolar lavage fluid of human volunteers exposed acutely to NO₂ or O₃.