Contribution of Lung Macrophages to the Inflammatory Responses Induced by Exposure to Air Pollutants

Figure 4

Relationship between the fraction of AMs that phagocytosed PM₁₀ particles and the transit time of PMN though the bone marrow. Rabbits were exposed to 5 mg PM₁₀ (EHC-93) twice a week for 4 weeks, and AMs with particles in their cytoplasm were enumerated using quantitative histological methods. Dividing PMNs in the marrow were labeled with 5-bromo-2-deoxyuridine and the transit time of PMN through the bone marrow was measured. Faster transit times of PMN through the marrow were associated with more AMs with phagocytosed particles (𝑅²=0.46, 𝑃<0.05) [56].