Increased mucociliary transport by adrenergic stimulation

Tracheobronchial clearance of inhaled 6mum Teflon particles (density 2 gm/cu cm) tagged with technetium 99m was studied in healthy subjects by external measurement of the radioactivity in the lungs for two hours. Clearance, salivary secretion, blood pressure, and heart rate were determined in eight subjects after double-blind, subcutaneous administration of 0.25 mg terbutaline sulfate, a beta-adrenoceptor stimulating compound and vehicle, respectively, in a crossover study. Terbutaline produced a marked increase in clearance and a slight increase in heart rate, but had no important effect on salivary secretion or blood pressure. The result indicates that the blood concentrations of catecholamines might be of importance for the regulation of the mucociliary transport rate.