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Updated: Aug 10, 2026
Generation of a Chronic Obstructive Pulmonary Disease Model in Mice by Repeated Ozone Exposure
Published on: August 25, 2017
Activity changes of pulmonary macrophages after in vivo exposure to ozone as demonstrated by cell adherence
Abstract:
Macrophages obtained by lavage from the lungs of rats exposed to 0.1 or 0.2 mg/m3 (0.05 or 0.10 ppm) ozone (O3) for 16 h show increased activity as measured in vitro by cell adherence to nylon fiber. A difference in adherence is noticed between macrophages occurring in first or second lung washings. The latter are less sensitive to ozone stimulation. At ozone doses higher than 0.2 mg/m3, the effect disappears and is even negative for second-washing macrophages after exposure of rats to 0.8 mg/m3 (0.4 ppm). The increased activity observed after exposure to the lower levels of O3 is explained as a defensive reaction of the organism. Failure to stimulate activity or a decrease of activity, observed at the higher O3 concentrations, may point to adverse events.
Insights
Low-level ozone exposure enhances rat lung macrophage activity, suggesting a defense mechanism. Higher ozone concentrations, however, impair macrophage function, indicating potential adverse health effects.
Area of Science:
- Environmental toxicology
- Cellular immunology
- Respiratory medicine
Background:
- Ozone (O3) is a major air pollutant with known respiratory effects.
- Macrophages play a crucial role in lung defense and inflammation.
- Understanding ozone's impact on macrophage function is vital for public health.
Purpose of the Study:
- To investigate the effect of varying ozone (O3) concentrations on rat lung macrophage activity.
- To determine if ozone exposure influences macrophage adherence to nylon fiber.
- To differentiate the response of macrophages from sequential lung lavages.
Main Methods:
- Rats were exposed to different concentrations of ozone (0.1, 0.2, and 0.8 mg/m3) for 16 hours.
- Macrophages were collected via sequential lung lavages (first and second washes).
- Macrophage activity was assessed in vitro by measuring cell adherence to nylon fiber.
Main Results:
- Low ozone concentrations (0.1-0.2 mg/m3) increased macrophage adherence, particularly in the first lung washing.
- Macrophages from the second lung washing showed reduced sensitivity to ozone stimulation.
- Higher ozone concentrations (≥0.2 mg/m3) diminished or reversed the stimulatory effect, especially in second-washing macrophages.
Conclusions:
- Increased macrophage activity at low ozone levels suggests a protective biological response.
- Impaired macrophage function at higher ozone concentrations may indicate cellular damage or toxicity.
- Sequential lung lavage reveals differential sensitivity of macrophage populations to ozone exposure.
