Eosinophilic airway inflammation induced by repeated exposure to cigarette smoke.
Acute exposure to cigarette smoke causes airway hyperresponsiveness (AHR) in guinea-pigs, which resolves within a few hours. Repeated exposure may have a different effect on the airways. To address this question, guinea-pigs were repeatedly exposed to cigarette smoke (six cigarettes for 1 h x day(-1)) for 14 consecutive days. Airway responsiveness to inhaled histamine and differential cell counts in bronchoalveolar lavage fluid (BALF) were evaluated 1 day after the last exposure. Significant neutrophilia in BALF was observed after 3 days of smoke exposure. Significant eosinophilia in BALF and AHR were observed after 14 days of smoke exposure, but not after 3 or 7 days of smoke exposure. These changes persisted until 3 days after the last exposure and resolved 7 days afterwards. Histologically, the recruited eosinophils were observed predominantly in the airways, but not in the alveoli. Treatment with E-6123, a specific platelet-activating factor receptor antagonist (1 mg x kg(-1) x day(-1) p.o. during smoke exposure) significantly inhibited the eosinophil influx and AHR. Repeated exposure to cigarette smoke may induce prolonged airway inflammation and airway hyperresponsiveness in guinea-pigs. Platelet-activating factor or platelet-activating factor-like lipids may play a key role in airway hyperresponsiveness, presumably by the induction of eosinophilic airway inflammation.
Matsumoto
K
K
Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Aizawa
H
H
Inoue
H
H
Koto
H
H
Takata
S
S
Shigyo
M
M
Nakano
H
H
Hara
N
N
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D001980:Bronchi / Q000473:pathology*; D016535:Bronchial Hyperreactivity / Q000209:etiology* / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D006168:Guinea Pigs; D008297:Male; D010947:Plants, Toxic; D010972:Platelet Activating Factor / Q000378:metabolism; D011657:Pulmonary Eosinophilia / Q000209:etiology* / Q000473:pathology; D012906:Smoke / Q000009:adverse effects*; D013997:Time Factors; D014026:Nicotiana; D014230:Triazoles / Q000494:pharmacology
D001381:Azepines; D010972:Platelet Activating Factor; D012906:Smoke; D014230:Triazoles; C068033:E 6123