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2630872 
Journal Article 
Abstract 
Concentrated ambient fine particles (CAPs) elicit airway inflammation and hypersecretory hyperplasia in rats 
Lemos, M; Pastro, LD; Pedro, SSC; Saldiva, PHN 
2010 
Yes 
American Journal of Respiratory and Critical Care Medicine
ISSN: 1073-449X
EISSN: 1535-4970 
181 
A1145 
English 
WOS:000208771000146 
is part of a larger document 3452678 Proceedings of the American Thoracic Society 2010 International Conference, May 14-19, 2010, New Orleans
Rationale: São Paulo city air pollution often exceeds the World Health Organization's (WHO) daily average limit level of 25ug/m^3 of PM2.5. We aim to evaluate possible pulmonary effects of this concentration.

Methods: Inhalation exposures were conducted in a mobile laboratory equipped with a Harvard fine particle concentrator parked at the University of São Paulo campus. Wistar rats (n=20) were exposed to concentrated ambient fine (PM2.5) particles (CAPs) or filtered air for 15 consecutive days, 5 hours per day. After the period of exposition, these rats were anesthetized with an association of intraperitoneal ketamine (75mg/kg) and xylazine (15mg/kg), and sacrificed by exsanguination of abdominal aorta. Lungs were processed for histological and morphometric analysis of hypersecretory hyperplasia in axial airways and semi-quantitative analysis of airways inflammation was performed.

Results: Lung histological descriptive analysis showed evident alteration on CAPs-exposed animals. The most conspicuous alteration found was observed on the bronchiole wall at the transition between the terminal bronchiole and alveoli territory, characterized by the presence of inflammatory infiltrate. Macrophages and neutrophils accumulated on the alveoli lumen of the center acinar gas exchange space. The number of mucous cells, specially acid mucine secretory cells, were increased in exposed rats. This is a stereotyped response of the mucosa to a chronic aggression, which was previously shown in our group.

Conclusion: These data suggest that the inhalation of CAPs concentration, even within the WHO limit levels of PM2.5, elicit hypersecretion of acid mucus and airway inflammation. 
American Thoracic Society 2010 International Conference 
New Orleans, LA 
May 14-19, 2010