MODULATION OF THE IONIC MILIEU OF THE AIRWAY IN HEALTH AND DISEASE

Airway surface liquid (ASL) is an integral part of lung defense mechan isms. Ion transport by airway epithelia regulates the volume and compo sition of this fluid. A better understanding of the mechanisms of ion transport will enable the development of new therapies for airway dise ases associated with defects in these mechanisms. A useful model of a disease with abnormal airway epithelial ion transport is cystic fibros is (CF), a distinct genetic syndrome of altered lung defense mechanism s characterized by chronic bacterial infection and a steady decline in lung function. Traditional therapies for CF include antibacterial dru gs and augmentation of clearance of secretions, but investigators are now studying pharmacological approaches to target the more basic defec t of the disease, i.e. abnormal sodium and chloride ion transport. Ear ly treatment in childhood, prior to lung damage, might prevent or at l east retard the decline in pulmonary function that remains the hallmar k of CF. Ion transport dysfunction may also contribute to other airway diseases such as asthma and chronic bronchitis. Pharmacological inter vention at this level may prove beneficial in these common lung diseas es as well.