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Azithromycin protects against hyperoxic lung injury in neonatal rats
Hubert O Ballard1, Philip Bernard, Joseph Qualls
1Department of Pediatrics, University of Kentucky Medical Center, Lexington, KY 40536-305, USA. hoball@uky.edu
Insights
Azithromycin improved survival and reduced lung damage in a rat model of bronchopulmonary dysplasia (BPD). This macrolide antibiotic decreased emphysematous changes and inflammation markers in the lungs of affected pups.
Area of Science:
- Neonatal Medicine
- Pulmonology
- Pharmacology
Background:
- Bronchopulmonary dysplasia (BPD) is a chronic lung disease in premature infants, characterized by inflammation and fibrosis.
- BPD leads to significant morbidity and mortality, with current treatments offering limited efficacy.
- Understanding the pathological mechanisms of BPD is crucial for developing effective therapeutic strategies.
Purpose of the Study:
- To investigate the potential therapeutic effects of azithromycin in an animal model of BPD.
- To determine if azithromycin can reduce lung injury, inflammation, and mortality associated with hyperoxia-induced BPD.
- To evaluate the impact of azithromycin on key pathological markers of BPD.
Main Methods:
- Sixty-three rat pups were randomly assigned to control, hyperoxia, or hyperoxia plus azithromycin groups.
- Hyperoxia groups were exposed to >95% oxygen from postnatal days 4-14.
- Lung histology (mean linear intercept) and interleukin-6 (IL-6) levels were assessed on day 14.
Main Results:
- Azithromycin treatment significantly improved survival rates in the hyperoxia group compared to untreated hyperoxia controls.
- Mean linear intercept, indicating alveolar size and emphysematous change, was significantly reduced in azithromycin-treated pups.
- Interleukin-6 (IL-6) levels, a marker of lung inflammation, were significantly lower in the lungs of azithromycin-treated pups.
Conclusions:
- Azithromycin demonstrates a protective effect against hyperoxia-induced lung injury in a rat model of BPD.
- The findings suggest that azithromycin may be a promising therapeutic agent for preventing or treating BPD in premature infants.
- Further clinical studies are warranted to confirm the efficacy and safety of azithromycin for BPD management.
Abstract:
Bronchopulmonary dysplasia (BPD) is a pulmonary disorder that causes significant morbidity and mortality in premature infants. BPD is pathologically characterized by inflammation, fibrosis, and mucosal necrosis, which leads to emphysematous coalescence of alveoli. We tested the hypothesis that azithromycin, a macrolide antibiotic, would decrease the severity of lung injury in an animal model of BPD. Sixty-three rat pups were randomly divided equally into control, hyperoxia, and hyperoxia plus azithromycin groups. The hyperoxia groups were exposed to > 95% oxygen from days of life 4 to 14. On day 14, the animals were processed for lung histology and tissue analysis. Lung morphology was assessed by mean linear intercept, a measure of alveolar size, with larger values corresponding to lungs that are more emphysematous. The degree of lung inflammation was assessed by quantifying interleukin-6 (IL-6) from lung homogenate. Fifty pups survived to day 14 (control = 21, hyperoxia = 11, hyperoxia + azithromycin = 18). Mortality was increased in the hyperoxia group versus the control group (p < .0001). Treatment with azithromycin improved survival in animals subjected to hyperoxia (p < .05). Azithromycin significantly decreased lung damage as determined by the mean linear intercept in the hyperoxia groups (p < .001). Finally, azithromycin-treated pups had lower levels of IL-6 in lung homogenate from the hyperoxia groups (p < .05). Azithromycin treatment resulted in improved survival, less emphysematous change, and decreased IL-6 levels in an animal model of BPD.
