[Bronchial secretions: biochemical study. Physiopathological aspects].

Among the chief constituents of bronchial secretions, serum or mucus proteins and mucins are the parameters enabling definition of the functional state of the tracheo-bronchial mucosa. The use of bronchial detergents in normal subjects or subjects with moderate secretions leads to the study of physiological sputum or to definition of the evolution of chronic bronchitis. Results of immunoglobulins G and A dosages, values of IgA 7S/IgA 11S and of IgA/serum albumin ratio are reported. In the same way, the equilibrium of secretion of mucins estimated by the percentage of the different classes of mucins separated according to their acidity degree is an evaluation element of the evolution degree of chronic bronchitis. The studies of correlation between rheological properties and chemical structure of bronchial secretions are reported. They postulate an original concept on the use of mucolytics.