Pulmonary consequences of a deep breath revisited.
About two decades ago, a model was proposed for surfactant release by lung distension. This model implies rapid fusion of lamellar bodies (LBs) with the plasma membrane followed by quick release of surfactant into the alveolus, as reflected by immediate facilitation of lung inflation after a single deep breath. Recent experimental evidence indicates that this two-pool model (intracellular versus alveolar surfactant pool) has to be refined by introducing a third pool, which resides in fused but non-released LBs. Here we discuss the implication of this additional pool for strain-induced surfactant secretion and propose a revised model for the sequence of events following a single deep breath.
Dietl
Paul
P
Department of Physiology, Medical University of Innsbruck, Innsbruck, Austria. paul.dietl@uibk.ac.at
Frick
Manfred
M
Mair
Norbert
N
Bertocchi
Cristina
C
Haller
Thomas
T
D000818:Animals; D001696:Biomechanical Phenomena; D002118:Calcium / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology; D005089:Exocytosis; D005456:Fluorescent Dyes; D006801:Humans; D008168:Lung / Q000502:physiology*; D008561:Membrane Fusion; D008954:Models, Biological; D011650:Pulmonary Alveoli / Q000502:physiology; D011663:Pulmonary Surfactants / Q000378:metabolism; D012119:Respiration
D005456:Fluorescent Dyes; D011663:Pulmonary Surfactants; D002118:Calcium