Effects on Serial-Day Exposure to Nitrogen Dioxide on Airway and Blood Leukocytes211 and Lymphocyte Sub-Sets

摘要

Nitrogen dioxide is a free radical and oxidant gas present in both indoor and211u001eoutdoor air. Inhalation of NO2 could cause airway inflammation and also decrease 211u001elocal of systemic immune function by changing the distribution of lymphocyte 211u001esubsets, or inhibiting lymphocyte activation. This experiment tested the 211u001ehypothesis that exposure to NO2 would (1) increase leukocytes in brochoalveolar 211u001elavage; (2) change the distribution of lymphocyte subsets and inhibit lymphocyte 211u001eactivation in bronchoalveolar lavage and peripheral blood and (3) increase 211u001eproteins in BAL. Within a counter-balanced, repeated-measures design, fifteen 211u001ehealthy volunteers were exposed to filtered air or 2.0 ppm no2 for 4 hours per 211u001eday, alternating 30 min. periods of rest and exercise, for 3 consecutive days. 211u001eThe results of this experiment demonstrate that exposure to 2.0 ppm NO2 for 4 211u001ehours per day on 3 consecutive days produces an increase in neutrophils in the 211u001eBfx (defined as the first 15 ml. of the bronchoalveolar lavage fluid) and a 211u001edecrease in CD3+CD4+ cells in the brochoalveolar lavage.