Airway responsiveness to acetylcholine in congenitally bronchial-hypersensitive (BHS) and bronchial-hyposensitive (BHR) guinea pigs in vivo and in vitro.
Exp Anim
; 47(3): 173-81, 1998 Jul.
Article
em En
| MEDLINE
| ID: mdl-9816493
ABSTRACT
The characteristics of airway responsiveness to acetylcholine (ACh) in congenitally bronchial-hypersensitive (BHS) and bronchial-hyposensitive (BHR) guinea pigs were clarified in vivo and in vitro. We measured the change in ventilatory mechanics in response to ACh inhalation by means of the bodyplethysmograph and the contractile responses of isolated trachea to ACh and carbachol (CCh). Further, muscarinic receptor subtypes involved these responses were identified. The basal values for ventilatory mechanics in BHS were not significantly different from those in BHR. Respiratory resistance to ACh was progressively increased in a time- and dose-dependent manner in BHS. The contractile responses of tracheal smooth muscle to ACh in BHS were significantly greater than those in BHR, but CCh-induced responses in BHS and BHR were similar. ACh- and CCh-induced contractions were mediated via M3 receptors. These results suggested that the falling-down of BHS in response to ACh inhalation was caused by the strong constriction of the airway and the reduction in ventilation. Moreover, the airway hyperresponsiveness to ACh in BHS might be partly dependent on the change in acetylcholinesterase activity.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças dos Roedores
/
Acetilcolina
/
Hiper-Reatividade Brônquica
/
Cobaias
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Exp Anim
Assunto da revista:
MEDICINA VETERINARIA
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Japão