Figure 4

Lung inflammation is still present in lung tissue after smoking cessation. Representative photomicrographs of hematoxylin and eosin stained lung tissue of air-exposed mice (A), smoke-exposed mice (B), smoke-exposed mice 8 weeks after smoking cessation (C). Magnification, ×100. The histological sections were scored for the presence of peribronchial and perivascular inflammation (D). Total lung inflammation was defined as the average of the peribronchial and perivascular inflammation scores. n = 4-5 animals per group. Values are expressed as mean +/- S.E.M. ***P ≤ 0.001; significantly different from the control group.