title: Long-term exposure to ultrasonically nebulized distilled water and saline causes cellular influx and oxidative stress in lung tissue of rats.
abstract: OBJECTIVE
  The aim of this study was to evaluate of the effect of distilled water and saline ultrasonic nebulization on the inflammatory and oxidative stress responses and on the lower airway architecture.
  
  
  METHODS
  Twenty-one male Fischer rats were distributed into 3 groups of 7 animals each: a control group (CG), exposed to ambient air; a saline group (SG), exposed to 0.9% sodium chloride (NaCl); and a group exposed to distilled water (DWG). The exposure was carried out in a box attached to an ultrasonic inhaler, occurring for 20 min, 3 times a day for 6 months. At 24h after the last exposure, the animals were euthanized. The bronchoalveolar lavage fluid (BALF) and lungs were collected for study.
  
  
  RESULTS
  There was an increase of inflammatory cells in the pulmonary tissue BALF in the DWG compared with the CG. The DWG showed an increase of inflammatory cells compared with the SG and CG. The DWG and SG had higher NADPH oxidase activity than the CG. The volume density (Vv) of the alveolar septum was higher in the DWG than in the SG and CG, and the DWG also had a higher Vv of collagen fibers than the other 2 groups. The DWG presented elevated content of thiobarbituric acid reactive substances in lung homogenates relative to the SG and CG.
  
  
  CONCLUSIONS
  The ultrasonic nebulization of distilled water increased the influx of inflammatory cells and oxidative damage, and promoted changes in the lung architecture.
authors.affiliation: a Laboratory of Experimental Pathophysiology (LAFEX), Department of Biological Sciences (DECBI) , Center of Research in Biological Sciences (NUPEB), Federal University of Ouro Preto (UFOP) , Ouro Preto, MG, Brazil.
authors.forename: Keila Karine Duarte
authors.initials: KK
authors.lastname: Campos
authors.affiliation: b Graduating in Medicine, School of Medicine , Federal University of Ouro Preto (UFOP) , Ouro Preto, MG, Brazil.
authors.forename: Simone Floresta
authors.initials: SF
authors.lastname: Leal
authors.affiliation: c Laboratory of Metabolic Biochemistry (LBM), Department of Biological Sciences (DECBI), Center of Research in Biological Sciences (NUPEB) , Federal University of Ouro Preto (UFOP) , Ouro Preto, MG, Brazil.
authors.forename: Daniela Caldeira
authors.initials: DC
authors.lastname: Costa
authors.affiliation: d Laboratory of Morphopathology (LMP), Department of Biological Sciences (DECBI), Center of Research in Biological Sciences (NUPEB) , Federal University of Ouro Preto (UFOP) , Ouro Preto , MG , Brazil.
authors.forename: Wanderson Geraldo
authors.initials: WG
authors.lastname: de Lima
authors.affiliation: a Laboratory of Experimental Pathophysiology (LAFEX), Department of Biological Sciences (DECBI) , Center of Research in Biological Sciences (NUPEB), Federal University of Ouro Preto (UFOP) , Ouro Preto, MG, Brazil.
authors.forename: Frank Silva
authors.initials: FS
authors.lastname: Bezerra
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D057168:Distillation; D008163:Luminescent Measurements; D008168:Lung / Q000378:metabolism / Q000473:pathology*; D008297:Male; D019255:NADPH Oxidases / Q000502:physiology; D009330:Nebulizers and Vaporizers; D009504:Neutrophils / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000378:metabolism; D012965:Sodium Chloride / Q000008:administration & dosage*; D014465:Ultrasonics; D014867:Water
chemical_list: D017382:Reactive Oxygen Species; D014867:Water; D012965:Sodium Chloride; D002374:Catalase; D019255:NADPH Oxidases
keywords: distilled water; lung; oxidative stress; rats; saline