Mucociliary transport system

The supplementary presence of viruses, bacteria, air pollutants or microparticles can further trigger or support such inflammation. Cytotoxic mediators of the late phase of inflammation are additionally responsible for disorders of the mucociliary transport system, epithelial damage and dysfunction of the immunological mucosa defense against viruses and bacteria. 

Figure 9 Effect of pulmonary dissolution rate on pulmonary selectivity. The dose of 300 p,g was allowed to dissolve immediately (A), with a half-life of 3 hr (B), or with a half-life of 24 hr (C). Pulmonary selectivity [area between pulmonary (upper line) and systemic (lower line) receptor occupancies] observed in A-C are summarized in D. The dose was given once a day at steady state. A slower release/dissolution of the drug in the lung does significantly increase pulmonary selectivity however, very slow dissolution rates further decrease pulmonary selectivity as the undissolved drug particles are removed from the lung by the mucociliary transport system.

Winters, S. L. Yeates, D. B. (1997). "Roles of hydration, sodium, and chloride in regulation of canine mucociliary transport system." JAppl Physiol, 83(4), 1360-9. 

The mean linear velocity of mucus, obtained from ten studies using instillation, was 14 5,5 mm/min, whereas that obtained from 13 studies using inhalation was 5.3 1.3 mm/min (2). The velocities measured after bronchoscopic instillation were higher and more variable than those measured after inhalation. This could be due to stimulation of the mucociliary transport system, either by... 

In addition to these classic responses, activation of sensory nerves can cause an increase in bronchial blood flow (8), bronchomotor tone (1), mueous secretion (9-12), and ciliary beat frequency (13), and possibly an increase of transepithelial fluid transport (14,15). In concert, these effects on the components of the mucociliary transport system are likely to cause an increase in mucoeiliary... 

Yeates DB. Inhibitory and excitatory neural regulation of the mucociliary transport system. In Baum G, ed. Cilia, Mucus and Mucociliary Interactions. New York Marcel Dekker, 1997 28-38. 

The first purified and characterized drug substances were administered as aerosols as a topical treatment for asthma approximately 50 years ago. More recently, drugs have been evaluated for systemic delivery. For each category of drug the mechanism of clearance from the airways must be considered. These mechanisms may be listed as mucociliary transport, absorption, and cell-mediated translocation. The composition and residence time of the particle will influence the mechanism of clearance. 

The bronchodilation produced by the methylxanthines is the major therapeutic action in asthma. Tolerance does not develop, but adverse effects, especially in the central nervous system, may limit the dose (see below). In addition to their effect on airway smooth muscle, these agents—in sufficient concentration—inhibit antigen-induced release of histamine from lung tissue their effect on mucociliary transport is unknown. 

Aspden, T.J. Mason, J.D. Jones, N.S. Lowe, J. Skaugrud, O. Ilium, L. Chitosan as a nasal delivery system the effect of chitosan solutions on in vitro and in vivo mucociliary transport rates in human turbinates and volunteers. J. Pharm. Sci. 1997, 86 (4), 509-513. 

In summary, the rheologieal eharaeteristies of normal mucus are very well matched with the characteristics of the ciliary propulsion system. Mucociliary transport depends on the interplay between three eomponents—the cilia, pericili-aiy fluid, and mucus—with the surfactant film at the mucus-air interface (44,45,81). The glycoproteins are most important in providing the appropriate levels of elasticity, viscosity, and cohesiveness for mucous flakes and sheets to be optimally propelled (82). 

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