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Updated: Dec 3, 2025
Isolation of Pulmonary Artery Smooth Muscle Cells from Neonatal Mice
Published on: October 19, 2013
CPAP protects against hyperoxia-induced increase in airway reactivity in neonatal mice
Peter M MacFarlane1, Catherine A Mayer1, Anjum Jafri1
1Department of Pediatrics, Division of Neonatology, Rainbow Babies & Children's Hospital, Case Western Reserve University, Cleveland, OH, USA.
Insights
Continuous positive airway pressure (CPAP) and hyperoxia alone worsen airway reactivity in newborn mice. However, combining CPAP with mild hyperoxia normalizes airway function and reduces adverse lung remodeling effects.
Area of Science:
- Neonatal respiratory support
- Pulmonary development
- Airway hyperreactivity
Background:
- Oxygen and CPAP are standard respiratory support for preterm infants.
- Animal models suggest hyperoxia and CPAP can negatively impact lung development.
- Investigating combined effects on neonatal airway function and morphology is crucial.
Purpose of the Study:
- To examine the impact of combined neonatal hyperoxia and CPAP on mouse airway function and morphology.
- To understand the interaction between mechanical stretch and hyperoxia in immature airways.
Main Methods:
- Newborn mice received daily hyperoxia (40% O2) with or without CPAP for 7 days.
- Airway hyperreactivity and lung morphology were assessed 2 weeks post-treatment.
- Evaluated epithelial and smooth muscle proliferation.
Main Results:
- CPAP and hyperoxia individually increased airway reactivity and smooth muscle/epithelial proliferation.
- Combined CPAP and hyperoxia exposure normalized airway reactivity.
- Combined treatment also normalized smooth muscle and epithelial proliferation to control levels.
Conclusions:
- Combined CPAP and mild hyperoxia mitigate adverse airway remodeling seen with individual treatments.
- The interaction between CPAP-induced stretch and hyperoxia influences immature airway development.
- Findings have implications for airway disease in former preterm infants on non-invasive support.
Background:
Oxygen and continuous positive airway pressure (CPAP) are primary modes of respiratory support for preterm infants. Animal models, however, have demonstrated adverse unintended effects of hyperoxia and CPAP on lung development. We investigate the effects of combined neonatal hyperoxia and CPAP exposure on airway function and morphology in mice.
Methods:
Newborn mice were exposed to hyperoxia (40% O2) 24 h/day for 7 consecutive days with or without daily (3 h/day) concomitant CPAP. Two weeks after CPAP and/or hyperoxia treatment ended, lungs were assessed for airway (AW) hyperreactivity and morphology.
Results:
CPAP and hyperoxia exposure alone increased airway reactivity compared to untreated control mice. CPAP-induced airway hyperreactivity was associated with epithelial and smooth muscle proliferation. In contrast, combined CPAP and hyperoxia treatment no longer resulted in increased airway reactivity, which was associated with normalization of smooth muscle and epithelial proliferation to values similar to untreated mice.
Conclusions:
Our data suggest that the combination of CPAP and hyperoxia decreases the adverse consequences on airway remodeling of either intervention alone. The complex interaction between mechanical stretch (via CPAP) and hyperoxia exposure on development of immature airways has implications for the pathophysiology of airway disease in former preterm infants receiving non-invasive respiratory support.
Impact:
CPAP and mild hyperoxia exposure alone increase airway reactivity in the neonatal mouse model. In contrast, combined CPAP and hyperoxia no longer induce airway hyperreactivity. Combined CPAP and hyperoxia normalize smooth muscle and epithelial proliferation to control values. Interaction between CPAP-induced stretch and mild hyperoxia exposure on immature airways has important implications for airway pathophysiology in former preterm infants.
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