title: [An inhalation chamber model for controlled studies of tobacco smoke toxicity in rodents].
abstract: BACKGROUND
  Smoking is a serious worldwide public health problem. Animal models act as a bridge between laboratory and human studies. The models applied are difficult to reproduce because of the use of different types of inhalation chambers and mainly because of the lack of continuous monitoring of smoke concentration.
  
  
  OBJECTIVE
  To develop an inhalation chamber for rats (with only the nose exposed) in which the amount of carbon monoxide (CO) can be maintained and monitored constantly.
  
  
  METHODS
  Male Wistar rats weighing 250g were exposed to 50ppm CO produced by the smoke from a filter-free cigarette. The animals were submitted to a single 2-h exposure and then sacrificed at 0, 4, 24 and 48h. The control group was left restrained inside the small perpendicular chambers, receiving only 5L/min of compressed air.
  
  
  RESULTS
  The model was able to increase HbCO levels immediately after the end of exposure (p<0.001), with a decrease being observed from 2h onwards when compared to the levels of the control group. Plasma cotinine increased immediately after exposure, and showed still detectable levels at 2 and 4h (p<0.05).
  
  
  CONCLUSIONS
  We conclude that the presented inhalation chamber system is able to maintain a controlled CO concentration in a model in which small animals are exposed to the inhalation of cigarette smoke, permitting well-controlled studies, as well as investigations involving other toxic gases and air pollutants.
authors.affiliation: Pulmonary Rehabilitation Center, Universidade Federal de São Paulo, Brasil. joserjardim@yahoo.com.br
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Jardim
authors.forename: Luciana
authors.initials: L
authors.lastname: Bizeto
authors.forename: Anamaria
authors.initials: A
authors.lastname: Fleig Mayer
authors.forename: Aquiles
authors.initials: A
authors.lastname: Camelier
authors.forename: Fernanda Warken
authors.initials: FW
authors.lastname: Rosa
authors.forename: Daniele
authors.initials: D
authors.lastname: Oliveira
authors.forename: Daiane
authors.initials: D
authors.lastname: Azevedo
authors.forename: Paulo Hilário
authors.initials: PH
authors.lastname: Saldiva
authors.forename: Milton de Arruda
authors.initials: Mde A
authors.lastname: Martins
authors.forename: Jorge
authors.initials: J
authors.lastname: Bonassa
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Nascimento
mesh_terms: D000818:Animals; D001273:Atmosphere Exposure Chambers; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution