Effect of orally administered orciprenaline on tracheobronchial mucociliary clearance.

The relative effects of beta-2-adrenergic stimulation of mucociliary transport in the trachea and the bronchial airways was determined in 12 healthy non-smoking males using radioaerosol techniques with and without the oral administration of 20 mg of orciprenaline. Orciprenaline increased tracheal mucociliary transport rates (TMTR) from a control mean of 4.4 +/- 2.4 mm/min to 6.6 +/- 4.0 mm/min (p less than 0.01), but the percentage of particles cleared from the lung in 2 h was not significantly different in the drug study (44 +/- 14%) compared to the control study (48 +/- 19%). Furthermore, a strong positive correlation existed between TMTR and bronchial clearance that was lost after administration of orciprenaline. This study demonstrates that low doses of orally administered orciprenaline increased tracheal mucociliary transport but not bronchial clearance in healthy adults.