Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivo.
Clin Exp Allergy
; 33(12): 1747-53, 2003 Dec.
Article
em En
| MEDLINE
| ID: mdl-14656365
ABSTRACT
BACKGROUND:
Indoor formaldehyde (FA) might worsen allergies and be an underlying factor for the increasing incidence and severity of asthma; the exact mechanism, however, remains unclear.OBJECTIVE:
The present study examined the effects of repeated exposure to FA on methacholine- and antigen-induced bronchoconstriction in guinea-pigs in vivo.METHODS:
First, non-sensitized guinea-pigs were transnasally treated with 0.1 or 1.0% FA or saline three times a week for 6 weeks, and increasing concentrations of methacholine (50, 100, and 200 microg/mL) were inhaled at 5-min intervals. Second, guinea-pigs pre-treated with transnasal administration of FA or saline using the same protocol were passively sensitized with anti-ovalbumin (OA) serum 7 days before antigen challenge. Third, guinea-pigs were actively sensitized with OA and pre-treated with transnasal administration of FA or saline using the same protocol. The lateral pressure of the tracheal tube (Pao) was measured under anesthesia and artificial ventilation.RESULTS:
The antigen-induced increase in Pao in actively sensitized guinea-pigs was significantly potentiated by FA exposure in a dose-dependent manner. The dose-response curve of the methacholine-induced increase in Pao in non-sensitized guinea-pigs or of the antigen-induced increase in Pao in passively sensitized guinea-pigs was not altered by FA exposure. Transnasal administration of FA significantly increased the serum anti-OA homocytotropic antibody titre (IgG) as measured by the passive cutaneous anaphylaxis reaction in actively sensitized guinea-pigs.CONCLUSION:
The results suggest that repeated exposure to FA worsens allergic bronchoconstriction through enhancing antigen sensitization.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fixadores
/
Formaldeído
/
Hipersensibilidade
Limite:
Animals
Idioma:
En
Revista:
Clin Exp Allergy
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Japão