Possible function of bronchial surfactant.

In addition to stabilizing peripheral airways bronchial surfactant is essential for bronchoalveolar transport mechanisms including non-ciliary and ciliary mucus transport. Furthermore, it could play a role in the masking of smooth muscle receptors with respect to contractile stimuli. A model has recently been devised in which predominant impairment of the bronchial surfactant is induced by a combination of positive or negative pressure ventilation with tracheal saline instillation (approximately 3 ml/kg). It is shown that tracheal instillation or inhalation of surfactant could be a promising approach for the treatment of damage to the bronchial surfactant system. In vitro investigations of the transport properties of various phospholipid mixtures and of detergents revealed that the transport function of surface active materials is independent of both the hysteresis characteristics and the surface tension changes during compression and expansion in the Langmuir trough.