Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivo
Article first published online: 9 DEC 2003
Clinical & Experimental Allergy
Volume 33, Issue 12, pages 1747–1753, December 2003
How to Cite
Kita, T., Fujimura, M., Myou, S., Ishiura, Y., Abo, M., Katayama, N., Nishitsuji, M., Yoshimi, Y., Nomura, S., Oribe, Y. and Nakao, S. (2003), Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivo. Clinical & Experimental Allergy, 33: 1747–1753. doi: 10.1111/j.1365-2222.2003.01826.x
- Issue published online: 9 DEC 2003
- Article first published online: 9 DEC 2003
- Submitted 5 August 2002; revised 19 March 2003; accepted 11 August 2003
- antigen sensitization;
- bronchial asthma;
- repeated transnasal exposure
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 μg/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.