Molecular and functional changes of pulmonary surfactant in response to hyperoxia

摘要: Surfactant comprises phosphatidylcholine (PC) together with anionic phospholipids, neutral lipids, and surfactant proteins SP-A to-D. Its composition is highly specific, dipalmitoyl-PC, palmitoyl-myristoyl-PC, palmitoyl-palmitoleoyl-PC as its predominant PC species, but low polyunsaturated phospholipids. Changes in pulmonary metabolism function response to injuries depend on their duration whether adaptation can occur. We examined rats prolonged (7 days) versus acute (2 exposure non-lethal oxygen concentrations (85%) respect the of individual lung phospholipid molecular species. Progressive inflammation, structural alteration, involvement type II pneumocytes were confirmed by augmented bromodeoxyuridine incorporation, broadening alveolar septa, increased granulocyte, macrophage, SP-A, SP-D concentrations. was impaired after 2 days, normalized hyperoxia, which attributable inhibition not alteration SP-B/C Phospholipid pool sizes synthesis tissue, assessed [methyl-3H]-choline unchanged although 7 days they elevated 1.7-fold. By contrast, incorporation labeled into tissue pools lavage fluid decreased progressively. Moreover, arachidonic acid containing phospholipids at expense saturated palmitoyl-myristoyl-PC dipalmitoyl-PC. conclude a persisting impairment intracellular trafficking secretion newly synthesized PC, accompanied progressive increase spite recovery acutely adaptive overall synthesis. Pediatr Pulmonol. 2006, 41:1025–1039. © 2006 Wiley-Liss, Inc.