Premium
Chronic Intermittent Hypoxia Induces Airflow Limitation in a Rodent Model of Allergen‐Induced Lower Airway Inflammation
Author(s) -
Broytman Oleg,
Braun Rudolf K,
Pegelow David F,
Hsu PeiNing,
Mei Linda Song,
Koya Ajay K,
Bates Melissa L,
Morgan Barbara J,
Eldridge Marlowe,
Sorkness Ronald L,
Teodorescu Mihaela
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.lb797
Subject(s) - medicine , intermittent hypoxia , ovalbumin , hypoxia (environmental) , bronchoalveolar lavage , airway , inflammation , asthma , lung , ventilation (architecture) , obstructive sleep apnea , immunology , anesthesia , immune system , chemistry , mechanical engineering , engineering , organic chemistry , oxygen
Rationale Obstructive sleep apnea (OSA) aggravates asthma, but the mechanisms are unclear. Chronic intermittent hypoxia (CIH) is one hallmark feature of OSA. We tested the effects of CIH on lower airways in an ovalbumin (OVA) rodent model. Methods Four groups (n=5–6/group) of Brown‐Norway rats underwent CIH (10% FiO2, 30 episodes/h, 10h/day for 30 days) vs. normoxia (NORM) and OVA vs. vehicle (VEH). Lung physiology and bronchoalveolar lavage (BAL) WBC differentials were compared between groups, 2 days after last challenge. Results On lung physiology: 1) CIH reduced the Forced Expiratory Volume in 0.1 second (FEV 0.1 ) to Forced Vital Capacity (FVC) ratio (FEV 0.1 /FVC) (p=0.008) and peak expiratory flow (p=0.03); OVA did not affect these measures. 2) FVC was increased by CIH (p=0.0009), but reduced by OVA (p <0.0001). In the BAL: 1) CIH did not change total cell counts (p = 0.25); 2) CIH induced a 2.3‐fold reduction in % eosinophils (p = 0.001); 3) In OVA‐challenged rats, CIH increased neutrophil fraction among infiltrating granulocytes (p = 0.03, Figure). Conclusions CIH induces airflow limitation even in the absence of inhaled allergen. CIH induces a more neutrophil‐predominant response to allergen. These findings highlight the potential of OSA to aggravate lung dysfunction in patients with pre‐existent airway inflammation. Supported by UW‐Madison Department of Medicine Pilot Funding.