[The pathogenesis and morphogenesis of noninflammatory lung diseases in premature infants].

Studies of the morphofunctional status of the lungs in premature infants showed that the factors responsible for the immaturity of the bronchoalveolar tissue played a major role in the patho- and morphogenesis of noninflammatory conditions: atelectasis and hyaline membrane disease. Of special significance is inadequate differentiation of the alveolar parenchyma and blood-air barrier as well as the presence of large amounts of serotonin-containing APUD cells in the immature lungs. When released into the surrounding parenchyma under the influence of pathogenic factors, serotonin brings about the development of broncho- and vasoconstriction, microthrombosis, and increased permeability of the vascular walls, which induces the development of hyaline membrane disease in premature infants. The findings open up new possibilities for the elaboration of new prevention and therapy patterns in combating this condition.