LSC - 2018 - Resistive breathing aggravates pulmonary inflammation and emphysema in experimental models of chronic obstructive pulmonary disease

Abstract

Background: Our research group has shown that resistive breathing (RB) induces pulmonary inflammation in previously healthy animals. We hypothesized that RB would exacerbate pulmonary inflammation and emphysema, when superimposed on COPD animal models. Aim and Objective: To investigate the synergistic effect of RB on pulmonary inflammation and emphysema, when combined with experimental models of COPD. Methods: C57BL/6 mice were exposed to cigarette smoke (CS) for 1 or 6 months. In another group, mice were exposed to 0.75 units of elastase (PPE) intratracheally. Resistive breathing was applied by suturing a nylon band around the trachea to reduce surface area to half, for 24 hours following CS exposure or for the last 24 or 72 hours of 21 days after elastase treatment in total. Following RB, lung mechanics were measured and bronchoalveolar lavage (BAL) was performed. Emphysema was quantified by the Mean Linear (Lm) and the Destructive index (DI) in lung tissue sections. Surfactant Protein (SP)-D plasma levels were measured. Results: CS exposure for 1 and 6 months increased BAL cell number (p Conclusion: RB exacerbates pulmonary inflammation and emphysema in COPD animal models.