Antigen-induced airway inflammation in the Brown Norway rat results in airway smooth muscle hyperplasia.
J Appl Physiol (1985)
; 93(5): 1833-40, 2002 Nov.
Article
em En
| MEDLINE
| ID: mdl-12381772
ABSTRACT
Asthma is characterized by chronic airways inflammation, airway wall remodeling, and airway hyperresponsiveness (AHR). An increase in airway smooth muscle has been proposed to explain a major part of AHR in asthma. We have used unbiased stereological methods to determine whether airway smooth muscle hyperplasia and AHR occurred in sensitized, antigen-challenged Brown Norway (BN) rats. Ovalbumin (OA)-sensitized BN rats chronically exposed to OA aerosol displayed airway inflammation and a modest level of AHR to intravenously administered ACh 24 h after the last antigen challenge. However, these animals did not show an increase in smooth muscle cell (SMC) number in the left main bronchus, suggesting that short-lived inflammatory mechanisms caused the acute AHR. In contrast, 7 days after the last aerosol challenge, there was a modest increase in SMC number, but no AHR to ACh. Addition of FCS to the chronic OA challenge protocol had no effect on the degree of inflammation but resulted in a marked increase in both SMC number and a persistent (7-day) AHR. These results raise the possibility that increases in airway SMC number rather than, or in addition to, chronic inflammation contribute to the persistent AHR detected in this model.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Brônquios
/
Bronquite
/
Ovalbumina
/
Hiper-Reatividade Brônquica
/
Músculo Liso
Limite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Austrália