1. Radiofrequency therapy improves exercise capacity of mice with emphysema
- Author
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Marek Lipnicki, Chen Xi Yang, Lindsay S. Machan, Evan Goodacre, Dan Gelbart, Cheng Wei Tony Yang, Denny Wong, Jen-erh Jaw, Zoe White, Eran Elizur, Eun Jeong Annie Bae, Samuel V. Lichtenstein, Kim Wolff, Don D. Sin, Takeyuki Wada, Chung Yan Cheung, Pascal Bernatchez, Lauren H. Choi, and Mai Tsutsui
- Subjects
Male ,medicine.medical_specialty ,Swine ,medicine.medical_treatment ,Pulmonary Fibrosis ,Science ,Urology ,Diseases ,Pulmonary compliance ,Extracorporeal ,Article ,Mice ,Medical research ,Fibrosis ,Physical Conditioning, Animal ,medicine ,Animals ,Treadmill ,Adverse effect ,Saline ,Pancreatic elastase ,Lung Compliance ,COPD ,Multidisciplinary ,Exercise Tolerance ,Pancreatic Elastase ,business.industry ,respiratory system ,medicine.disease ,Radiofrequency Therapy ,respiratory tract diseases ,Mice, Inbred C57BL ,Pulmonary Emphysema ,Medicine ,business - Abstract
Background; Emphysema is a common phenotype of chronic obstructive pulmonary disease (COPD). Although resection of emphysematous tissue can improve lung mechanics, it is invasive and fraught with adverse effects. Meanwhile, radiofrequency (RF) treatment is an extracorporeal method that leads to tissue destruction and remodeling, resulting in “volume reduction” and overall improvement in lung compliance of emphysematous lungs. Whether these changes lead to improved exercise tolerance is unknown. Here, we investigated the effectiveness of RF treatment to improve the exercise capacity of mice with emphysema.Methods;Fifty-two mice (7 weeks of age) were used in this experiment. A bilateral emphysema model was created by intratracheally instilling porcine pancreatic elastase (PPE) (1.5U/100g body weight). RF treatment (0.5W/ g body weight) was performed extracorporeally 14 days later and mice were sacrificed after another 21 days. The exercise capacity of mice was measured using a treadmill. Treadmill runs were performed just before PPE instillation (baseline), before RF treatment and before sacrifice. Following sacrifice, lung compliance and mean linear intercept (Lm) were measured and fibrosis was assessed using a modified Ashcroft score.Results; There were 3 experimental groups: controls (instilled with saline, n=12), emphysema (instilled with porcine pancreatic elastase, PPE, n=11) and emphysema + treatment (instilled with PPE and given RF, n=9). At endpoint, the maximum velocity of the emphysema + treatment group was significantly higher than that of the emphysema group, indicating improved exercise tolerance (86.29% of baseline vs 61.69% of baseline, p=0.011). Histological analysis revealed a significant reduction in emphysema as denoted by Lm between the two groups (median 29.60 µm vs 35.68 µm, p=0.033). The emphysema + treatment group also demonstrated a higher prevalence of lung fibrosis (≧Grade 3) compared with the emphysema group (11.7% vs 5.4%, p
- Published
- 2021