title: Time course of pulmonary burden in mice exposed to residual oil fly ash.
abstract: Residual oil fly ash (ROFA) is a common pollutant in areas where oil is burned. This particulate matter (PM) with a broad distribution of particle diameters can be inhaled by human beings and putatively damage their respiratory system. Although some studies deal with cultured cells, animals, and even epidemiological issues, so far a comprehensive analysis of respiratory outcomes as a function of the time elapsed after exposure to a low dose of ROFA is wanted. Thus, we aimed to investigate the time course of mechanical, histological, and inflammatory lung changes, as well as neutrophils in the blood, in mice exposed to ROFA until 5 days after exposure. BALB/c mice (25 ± 5 g) were randomly divided into 7 groups and intranasally instilled with either 10 μL of sterile saline solution (0.9% NaCl, CTRL) or ROFA (0.2 μg in 10 μL of saline solution). Pulmonary mechanics, histology (normal and collapsed alveoli, mononuclear and polymorphonuclear cells, and ultrastructure), neutrophils (in blood and bronchoalveolar lavage fluid) were determined at 6 h in CTRL and at 6, 24, 48, 72, 96, and 120 h after ROFA exposure. ROFA contained metal elements, especially iron, polycyclic aromatic hydrocarbons (PAHs), and organochlorines. Lung resistive pressure augmented early (6 h) in the course of lung injury and other mechanical, histological and inflammatory parameters increased at 24 h, returning to control values at 120 h. Blood neutrophilia was present only at 24 and 48 h after exposure. Swelling of endothelial cells with adherent neutrophils was detected after ROFA instillation. No neutrophils were present in the lavage fluid. In conclusion, the exposure to ROFA, even in low doses, induced early changes in pulmonary mechanics, lung histology and accumulation of neutrophils in blood of mice that lasted for 4 days and disappeared spontaneously.
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Giovanna Marcella Cavalcante
authors.initials: GM
authors.lastname: Carvalho
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Lilian Katiê da Silva
authors.initials: LK
authors.lastname: Nagato
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Sheila da Silva
authors.initials: Sda S
authors.lastname: Fagundes
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Flávia Brandão
authors.initials: FB
authors.lastname: Dos Santos
authors.affiliation: Laboratory of Immunopharmacology, Department of Physiology and Pharmacodynamics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz Rio de Janeiro, Brazil.
authors.forename: Andrea Surrage
authors.initials: AS
authors.lastname: Calheiros
authors.affiliation: Laboratory of Radioisotopes, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Olaf
authors.initials: O
authors.lastname: Malm
authors.affiliation: Laboratory of Immunopharmacology, Department of Physiology and Pharmacodynamics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz Rio de Janeiro, Brazil.
authors.forename: Patricia Torres
authors.initials: PT
authors.lastname: Bozza
authors.affiliation: Laboratory of Experimental Air Pollution, Department of Pathology, School of Medicine, Universidade de São Paulo São Paulo, Brazil.
authors.forename: Paulo Hilário N
authors.initials: PH
authors.lastname: Saldiva
authors.affiliation: Laboratory of Macromolecular Metabolism Firmino Torres de Castro, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Débora Souza
authors.initials: DS
authors.lastname: Faffe
authors.affiliation: Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Patricia Rieken Macedo
authors.initials: PR
authors.lastname: Rocco
authors.affiliation: Laboratory of Respiration Physiology, Carlos Chagas Filho Institute of Biophysics, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
authors.forename: Walter Araujo
authors.initials: WA
authors.lastname: Zin
keywords: ROFA composition; air pollution; lung injury; lung mechanics; pulmonary histology; residual oil fly ash (ROFA)