[Normal and abnormal alveolar development].

INTRODUCTION: Alveolar growth predominantly occurs post-natally and is characterised by the multiplication of alveoli, the thinning of inter-alveolar walls, and the maturation of capillary vessels. STATE OF THE ART: Alveolar growth is controlled by numerous factors whose interactions remain poorly understood. Many phenomena can interfere with normal alveolar growth resulting in abnormal development and a reduction in alveolar surface. This is especially the case in premature human neonates, whose lungs are structurally and functionally immature. Oxygen therapy, mechanical ventilation, and airway inflammation may induce alveolar growth disorders in these children, resulting in the development of bronchopulmonary dysplasia. PERSPECTIVES AND
CONCLUSIONS: Further studies are needed to improve our knowledge about alveolar growth regulatory mechanisms so that better strategies can be developed to prevent these respiratory complications in premature neonates.