[Methods of studying mucociliary function].
The mucociliary system represents the first respiratory tract barrier which acts by removing insoluble particles from the conductive airways. Impairment of mucociliary clearance, due to respiratory mucus and ciliary activity abnormalities, leads to mucus stasis, responsible for infection and bronchial obstruction. In obstructive airway diseases, the efficiency of the mucociliary function can be investigated quantitatively by in vivo and in vitro tests. In vivo mucociliary clearance can be measured by radioactive marker techniques. In vitro tests can evaluate the physical properties and transportability of mucus. The ciliary function can easily be analyzed on ciliated cells collected by nasal or bronchial brushing. Coupled with respiratory function tests, the investigation of the mucociliary function by in vivo and in vitro tests, provides a guideline for selection and assessment of drugs used to correct mucociliary disorders.