Bronchial responsiveness in an elastase-induced mouse model of emphysema.
Bronchial responsiveness during methacholine (MCh) challenge was analysed in an elastase-induced mouse model of emphysema to explore the magnitude of the response in this model. Swiss mice were intratracheally instilled with saline or elastase (0.3 or 0.6 U). Twenty days afterward, mechanical ventilation data were collected from the closed and opened thorax of baseline and MCh (vehicle, 50 and 100 mg/mL) challenged mice. The lungs were prepared for morphometric analysis. In the 0.6 U group, airway resistance (Raw) and tissue elastance (H) were decreased, and hysteresivity (η) was increased (closed thorax). MCh increased Raw, G and H in all groups, but this increase was attenuated in the elastase-induced emphysema groups, the largest attenuation was observed in the 0.6 U (closed thorax condition). Elastase increased hyperinflation of the alveoli, alveolar collapse and the Lm and reduced the normal area. MCh reduced respiratory mechanics in elastase-induced emphysema, and this reduction was modulated by the collapsed and/or hyperinflated areas, which increased the heterogeneity of the lungs.
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil.
Luiz Marcelo Oliveira
LM
Santos
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil.
Daniela Aparecida
DA
de Brito Cervilha
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil.
Layla Dutra Marinho
LD
Cabral
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil.
Érika Kristina Incerpi
ÉK
Garcia
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil.
Vanessa Pereira
VP
Teixeira
Laboratory of Lung Pathology, University of São Paulo, São Paulo, Brazil.
Jôse Mára
JM
Brito
Department of Biomedical Engineering, University of Sao Paulo, São Paulo, Brazil.
Henrique Takachi
HT
Moriya
Laboratory of Physiology, Federal University of Alfenas, Minas Gerais, Brazil; Department of Biomedical Engineering, Boston University, Boston, MA, USA. Electronic address: soncinir@yahoo.com.br.
Roseli
R
Soncini
D000818:Animals; D016085:Bronchoconstrictor Agents; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004646:Emphysema / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology*; D008168:Lung / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D016210:Methacholine Chloride; D051379:Mice; D010196:Pancreatic Elastase; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D001261:Pulmonary Atelectasis / Q000188:drug therapy / Q000503:physiopathology; D012121:Respiration, Artificial; D015656:Respiratory Mechanics / Q000187:drug effects; D013909:Thorax / Q000503:physiopathology
D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride; D010196:Pancreatic Elastase
Airway resistance; Elastase; Emphysema; Hysteresivity