A new, simple method for measuring mucociliary clearance in guinea-pigs

Airway mucociliary transport (MCT), which continuously removes inhaled particles and cellular debris from deep in the lung, is impaired in a number of diseases such as bronchitis and asthma, In order to determine the effects of candidate drugs on MCT function in the airway, a new in situ method to measure MCT function was established, MCT function is represented by the distance a gelatin solution containing Evans blue as a marker mo,es after injection into the trachea, The basal rate of dye transport in non-treated guinea-pigs was 4.4 +/- 0.2 mm/min, The beta(2)-adrenoceptor agonist salbutamol (2, 6, 10, 20 mg/kg, po), dose-dependently accelerated the basal MCT rate, However, its effect was completely inhibited by pretreatment with the non-selective beta-adrenoceptor antagonist, propranolol (1 mg/kg, iv). MCT function in guinea-pigs,vas significantly attenuated to 2.6 +/- 0.3 mm/min by SO2 gas exposure. Salbutamol failed to prevent MCT dysfunction in SO2-exposed animals at doses previously shown to accelerate basal MCT rate. This simple method is useful for estimating MCT function in several airway disease models and for examining new drugs designed to improve MCT function in airway diseases. (C) 1999 Academic Press.