Mucocililary activity in the respiratory tract as influenced by prostaglandin E

Evidence is presented from in vitro experiments in over 1,100 animals that the long accepted hypothesis of a continuous tracheobronchial mucus blanket is untenable, since mucus is transported in the form of flakes, plaques and continuous streams. It is proposed that a liquid of low viscosity lies between the cilia and covers their tips. This liquid is either not transported or very slowly so. Mucus flakes and plaques are transported by the tips of the cilia over this interciliary liquid. Prostaglandin E1 (PGE1) in low concentrations caused lysis of stagnant flakes and plaques. In addition, it caused a marked increase in the quantity of the tracheobronchial fluid and no clear-cut effect on the rate of ciliary frequency. The possible involvement of adenyl cyclase in the response to PGE1 is discussed.