EFFECTS OF CIGARETTE SMOKE EXPOSURE AND CESSATION ON INFLAMMATORY CELLS AND MATRIX METALLOPROTEINASE ACTIVITY IN MICE

Abstract

B6C3F₁ female mice were exposed to cigarette smoke (CS) (250 mg/m³ total particulate material) or filtered air (FA), 6 hours/day, 5 days/week, for 6, 7, or 10 weeks, or to CS for 6 weeks, then FA for 1 or 4 additional weeks. Exposure to CS increased macrophages, neutrophils, lymphocytes, and matrix metalloproteinase (MMP)-2 and MMP-9 content in bronchoalveolar lavage fluid. Partial recovery of most lavage parameters (except lymphocytes) was observed 1 week after cessation of CS exposure with further reductions after 4 weeks, but interstitial inflammation persisted longer. These results support a role for MMPs in CS-induced emphysema and indicate that smoking cessation allows restoration toward normal homeostasis.

Keywords:

• chronic obstructive pulmonary disease
• cigarette smoke
• emphysema
• matrix metalloproteinase
• smoking cessation