[Pathologic bronchial secretions and mucociliary transport].
The tracheo-bronchial tree is covered over its whole surface with a thin layer of bronchial secretions, consisting principally of high molecular weight glycoproteins: Mucins, and various proteins of secretory and serum origin. The special biochemical structure of these various macromolecular components endow the secretions with rheological properties of viscosity and elasticity essential for their transportation by ciliary activity. In chronic hypersecretory states, the equilibrium of secretion of various biochemical components is disturbed. The equilibrium of synthesis of mucins is modified and the content of proteins of secretory origin, such as IgAs is decreased. By contrast, the transudation of proteins of plasma origin, such as serum albumin is increase. These biochemical changes, which are very marked during periods of bronchial secondary infection, are accompanied most often by hyperviscosity and hypoelasticity of the secretions which results in slowing of mucociliary drainage and encourages the retention of secretions. In individuals suffering from chronic hypersecretion, abnormalities of bronchial secretions and their effects upon mucociliary function may be assessed by various methods of investigation: 1--biochemical and rheological analysis of the sputum; 2--measurement "in vitro" of the rate of transport in an animal model. 3--study "in vivo" of muco-ciliary clearance by a radio-isotopic technique. These tests are precious information determining both the indications and effects of treatment designed to improve the efficacy of mucociliary transport.
D001980:Bronchi / Q000378:metabolism* / Q000502:physiology / Q000503:physiopathology; D002923:Cilia / Q000502:physiology*; D006801:Humans; D009093:Mucus / Q000502:physiology
Sécrétions bronchiques pathologiques et transport mucociliaire.