Abstract
Introduction: Chronic obstructive pulmonary disease (COPD), which mainly results from chronic exposure to tobacco smoke, is a major public health burden with no effective treatment. We have previously shown that hypoxia can induce lung growth in adult mice [1]. The aim of this study is to investigate if sustained hypoxia can restore the loss of alveolar surface area caused by tobacco smoke.
Methods: We exposed C57BL/6J mice to 6 months of tobacco smoke (250 mg/m3 suspended particles in 2.5 h/day) followed by 3 months of sustained hypoxia (SH) with an FiO2 of 10% and appropriate control groups (no smoke/normoxia (N)). Pulmonary function was measured in anesthetized mice. Following euthanasia lungs were processed for morphometry, mean airspace chord length (Lm) was measured and alveolar surface area was calculated.
Results: Mice exposed to tobacco smoke had a trend towards a lower alveolar surface area compared to control mice even 3 months after smoke cessation (p=0.10). SH increased total lung capacity, whereas Lm was unchanged. SH significantly increased the alveolar surface area in mice previously exposed to smoke (p=0.008, Fig. 1), but not in control mice.
Conclusions: Sustained hypoxia after cessation of tobacco smoking restores alveolar surface area in mice. Future studies of the underlying mechanisms might lead to potential therapies.
Reference:
1. Reinke et al, Am J Physiol Lung Cell Mol Physiol 2011, 300(2):L266-73.
- © 2011 ERS