[Non-respiratory lung function (problem status)]

Non-respiratory lung function (NFL) has been an area of intense scientific research for the past twenty years. Experts from the European Respiratory Society have developed a technical regulation that has made it possible to standardize the study of organic and inorganic volatile compounds both in the portion of exhaled air and in the collection of its condensate. The metabolic function of the pulmonary parenchyma is actively manifested in the regulation of water-electrolyte metabolism, as well as biologically active amines and peptides; unique properties of alveolocytes of the second type and alveolar macrophages in the synthesis and recycling of surfactant. A special role is played by the endotheliocytes of the pulmonary capillaries, which transform angiotensin-1 (deca peptide) into angiotensin-2 (octa peptide) with the help of an angiotensin-converting enzyme. The respiratory system is considered within the NFL as an active immunological organ. Bronchus-associated lymph nodes form mucosal immunity with the participation of secretory immunoglobulin class A, also participating in the formation of innate and acquired immunity. Clinical manifestations of immunopathological reactions of the respiratory system are diverse. Thus, in clinical practice, allergic reactions of both immediate and delayed types can be observed; granulomatous processes of the pulmonary parenchyma occupy a special place. In the mucous membrane of the respiratory tract, neuroepithelium can be identified, which plays an important role in the differentiation of cell structures and in the morphogenesis of lung tissue. However, the participation of the lungs in endocrinological reactions remains, at present, a poorly studied direction. The translation of scientific information on the metabolic, immunological and endocrinological functions of the lungs has made it possible to identify a number of biological markers in diseases such as bronchial asthma, COPD, lung cancer, and pneumonia. Studies of the proteome of exhaled air condensate have brought us closer to the discovery of new biological markers.