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Developmental changes in rat surfactant lipidomics in the context of species variability
Author(s) -
Bernhard Wolfgang,
Schmiedl Andreas,
Koster Grielof,
Orgeig Sandra,
Acevedo Christa,
Poets Christian F.,
Postle Anthony D.
Publication year - 2007
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.20657
Subject(s) - pulmonary surfactant , phospholipid , context (archaeology) , lipidomics , lung , phosphatidylcholine , respiratory system , physiology , medicine , biophysics , biology , endocrinology , biochemistry , membrane , paleontology
Abstract Lung surfactant comprises mainly phosphatidylcholine (PC) species together with phosphatidylglycerols and surfactant proteins (SP) SP‐A to ‐D. Changes in the concentrations of its principal components dipalmitoyl‐PC, palmitoylmyristoyl‐PC, palmitoylpalmitoleoyl‐PC relative to developmental, structural and physiological differences are only partially understood. Particularly, their attribution to differences in air–liquid interface curvature, compared with dynamic parameters, such as respiratory rate, are controversial. We postulated that during alveolarization the changes in these principal PC components of surfactant differ from those in other phospholipid parameters, and that across endothermic vertebrates their concentrations are related to lung physiology rather than structure. We therefore investigated in rats from postnatal day (d)1 to d42 the pattern of surfactant phospholipids relative to alveolarization (d4–d14), and we discuss these changes in terms of molecular adaptation to pulmonary structure or physiology. Contrary to mammals with advanced alveolarization and increased respiratory rate (RR) at term, concentrations of dipalmitoyl‐PC (49–52%) and palmitoylmyristoyl‐PC (7–9%) in lung lavage fluid were identical at d1 and d42. At d7–d14, when in rats RR is increased, palmitoyl‐myristoyl‐PC transiently increased by 2.5‐ to 3.9‐fold at the expense of dipalmitoyl‐PC (−32% to 34%) and palmitoyl‐palmitoleoyl‐PC (−16%). Other lipidomic changes followed essentially different patterns of increase or decrease. Palmitoyl‐myristoyl‐PC was increased in large aggregates suggesting that it is an integral component of active surfactant. In the overall context of vertebrates, irrespective of age and lung structure, fractions of palmitoyl‐myristoyl‐PC, dipalmitoyl‐PC and palmitoyl‐palmitoleoyl‐PC correlate with differences in RR rather than alveolar curvature. In adult mammals, however, only concentrations of palmitoyl‐palmitoleoyl‐PC correlate with RR. Pediatr Pulmonol. 2007; 42:794–804. © 2007 Wiley‐Liss, Inc.