Interleukin-8 inhalation directly provokes bronchoconstriction in guinea pigs.
BACKGROUND
Although it has been reported that the concentration of interleukin (IL)-8 in nasal lavage fluid and sputum and its production in bronchial epithelium were increased in asthmatic subjects, the direct effects of IL-8 on the airways in vivo is unclear.


METHODS
We examined bronchoconstriction in response to IL-8 inhalation through an endotracheal cannula in anesthetized, artificially ventilated guinea pigs.


RESULTS
Inhalation of IL-8 at concentrations of 1 and 10 microg/ml caused significant bronchoconstriction, as revealed by the elevation of pressure at the airway opening. Moreover, the bronchoconstriction induced by IL-8 was significantly inhibited by the antihistamines diphenhydramine and terfenadine, suggesting the involvement of histamine release in the IL-8-induced bronchoconstriction. No significant leukocyte infiltration was observed in the bronchoalveolar lavage fluid or histologic findings 25 min after the first IL-8 inhalation.


CONCLUSIONS
IL-8 provokes bronchoconstriction without leukocyte accumulation in the airways, mediated in part by histamine release, in guinea pigs.
Fujimura
M
M
Third Department of Internal Medicine, Kanazawa University School of Medicine, Japan.
Myou
S
S
Nomura
M
M
Mizuguchi
M
M
Matsuda
T
T
Harada
A
A
Mukaida
N
N
Matsushima
K
K
Nonomura
A
A
D000280:Administration, Inhalation; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016084:Bronchoconstriction / Q000187:drug effects* / Q000502:physiology; D004155:Diphenhydramine / Q000494:pharmacology; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D016209:Interleukin-8 / Q000008:administration & dosage / Q000494:pharmacology*; D016593:Terfenadine / Q000494:pharmacology
D006634:Histamine H1 Antagonists; D016209:Interleukin-8; D016593:Terfenadine; D004155:Diphenhydramine