Recombinant alpha 1-proteinase inhibitor blocks antigen- and mediator-induced airway responses in sheep.
J Appl Physiol (1985)
; 93(6): 1900-6, 2002 Dec.
Article
em En
| MEDLINE
| ID: mdl-12433933
ABSTRACT
Alpha(1)-proteinase inhibitor (alpha(1)-PI) is a natural serine protease inhibitor. Although mainly thought to protect the airways from neutrophil elastase, alpha(1)-PI may also regulate the development of airway hyperresponsiveness (AHR), as indicated by our previous findings of an inverse relationship between lung alpha(1)-PI activity and the severity of antigen-induced AHR. Because allergic stimulation of the airways causes release of elastase, tissue kallikrein, and reactive oxygen species (ROS), all of which can reduce alpha(1)-PI activity and contribute to AHR, we hypothesized that administration of exogenous alpha(1)-PI should protect against pathophysiological airway responses caused by these agents. In untreated allergic sheep, airway challenge with elastase, xanthine/xanthine oxidase (which generates ROS), high-molecular-weight kininogen, the substrate for tissue kallikrein, and antigen resulted in bronchoconstriction. ROS and antigen also induced AHR to inhaled carbachol. Treatment with 10 mg of recombinant alpha(1)-PI (ralpha(1)-PI) blocked the bronchoconstriction caused by elastase, high-molecular-weight kininogen, and ROS, and the AHR induced by ROS and antigen. One milligram of ralpha(1)-PI was ineffective. These are the first in vivo data demonstrating the effects of ralpha(1)-PI. Our results are consistent with and extend findings obtained with human plasma-derived alpha(1)-PI and suggest that alpha(1)-PI may be important in the regulation of airway responsiveness.
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Base de dados:
MEDLINE
Assunto principal:
Inibidores de Serina Proteinase
/
Alfa 1-Antitripsina
/
Hiper-Reatividade Brônquica
Limite:
Animals
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article