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Updated: May 12, 2026

Isolation of Mouse Respiratory Epithelial Cells and Exposure to Experimental Cigarette Smoke at Air Liquid Interface
Published on: February 21, 2011
Effects of cigarette smoking intensity on the mucociliary clearance of active smokers
Rafaella Fagundes Xavier1, Dionei Ramos, Juliana Tiyaki Ito
1Department of Physiotherapy, São Paulo State University, Presidente Prudente, São Paulo, Brazil.
Background:
Smoking impairs mucociliary clearance and increases respiratory infection frequency and severity in subjects with and without smoking-related chronic lung diseases.
Objective:
This study evaluated the effects of smoking intensity on mucociliary clearance in active smokers.
Methods:
Seventy-five active smokers were grouped into light (1-10 cigarettes/day; n = 14), moderate (11-20 cigarettes/day; n = 34) and heavy smokers (≥21 cigarettes/day; n = 27) before starting a smoking cessation programme. Smoking behaviour, nicotine dependence, pulmonary function, carbon monoxide in exhaled air (exCO), carboxyhaemoglobin (COHb) and mucociliary clearance measured by the saccharin transit time (STT) test were all evaluated. An age-matched non-smoker group (n = 24) was assessed using the same tests.
Results:
Moderate (49 ± 7 years) and heavy smokers (46 ± 8 years) had higher STT (p = 0.0001), exCO (p < 0.0001) and COHb (p < 0.0001) levels compared with light smokers (51 ± 15 years) and non-smokers (50 ± 11 years). A positive correlation was observed between STT and exCO (r = 0.4; p < 0.0001), STT and cigarettes/day (r = 0.3, p = 0.02) and exCO and cigarettes/day (r = 0.3, p < 0.01).
Conclusion:
Smoking impairs mucociliary clearance and is associated with cigarette smoking intensity.
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