Related Experiment Video
Updated: May 10, 2026
Modeling Dysplastic and Functional Lung Alveolar Repair after Influenza Infection
Published on: September 19, 2025
Viral bronchiolitis in young rats causes small airway lesions that correlate with reduced lung function
Ronald L Sorkness1, Renee J Szakaly, Louis A Rosenthal
11 The School of Pharmacy; The School of Medicine and Public Health Departments of.
Insights
Infant viral infections can cause lasting small airway dysfunction, a key factor in childhood asthma development. This study shows early viral injury leads to structural airway damage and persistent breathing problems into adulthood.
Area of Science:
- Pulmonary Medicine
- Pediatric Respiratory Research
- Animal Models of Airway Disease
Background:
- Infant wheezing from viral infections is linked to childhood asthma.
- Small airway dysfunction is a hallmark of childhood asthma.
- The long-term impact of early viral illness on small airway structure and function remains unclear.
Purpose of the Study:
- To investigate how post-bronchiolitis small airway lesions affect airway physiology.
- To determine if structural and functional airway deficits persist into adulthood in a rat model.
Main Methods:
- Brown Norway rats were inoculated with virus or sham at 3-4 weeks of age.
- Physiological assessments (respiratory system resistance, Newtonian resistance, tissue damping) were performed at 3 and 12-14 months.
- Lung sections were analyzed to quantify terminal bronchiolar lesions.
Main Results:
- Viral inoculation induced lesions in terminal bronchioles, reducing luminal area and branching.
- At 3 months, small airway lesions correlated with tissue damping, indicating distal airway obstruction.
- Older rats exhibited persistent small airway dysfunction and significantly increased Newtonian resistance.
Conclusions:
- Early-life viral airway injury can cause persistent small airway lesions.
- These lesions are quantitatively associated with physiological dysfunction in small airways.
- The observed airway defects persist into adulthood, potentially contributing to chronic respiratory conditions.
Abstract:
Viral illness with wheezing during infancy is associated with the inception of childhood asthma. Small airway dysfunction is a component of childhood asthma, but little is known about how viral illness at an early age may affect the structure and function of small airways. We used a well-characterized rat model of postbronchiolitis chronic airway dysfunction to address how postinfectious small airway lesions affect airway physiological function and if the structure/function correlates persist into maturity. Brown Norway rats were sham- or virus inoculated at 3 to 4 weeks of age and allowed to recover from the acute illness. At 3 to 14 months of age, physiology (respiratory system resistance, Newtonian resistance, tissue damping, and static lung volumes) was assessed in anesthetized, intubated rats. Serial lung sections revealed lesions in the terminal bronchioles that reduced luminal area and interrupted further branching, affecting 26% (range, 13-39%) of the small airways at 3 months of age and 22% (range, 6-40%) at 12 to 14 months of age. At 3 months of age (n = 29 virus; n = 7 sham), small airway lesions correlated with tissue damping (rs = 0.69) but not with Newtonian resistance (rs = 0.23), and Newtonian resistance was not elevated compared with control rats, indicating that distal airways were primarily responsible for the airflow obstruction. Older rats (n = 7 virus; n = 6 sham) had persistent small airway dysfunction and significantly increased Newtonian resistance in the postbronchiolitis group. We conclude that viral airway injury at an early age may induce small airway lesions that are associated quantitatively with small airway physiological dysfunction early on and that these defects persist into maturity.
