title: Composition, biophysical properties, and morphometry of plasma membranes in pulmonary interstitial edema.
abstract: We evaluated the changes in plasma membrane composition, biophysical properties, and morphology of pulmonary endothelial cells in anesthetized rabbits receiving 0.5 ml. kg(-1). min(-1) saline infusion for 180 min, causing mild interstitial edema. Plasma membrane fractions were obtained from lung homogenates with gradient centrifugation, allowing a sixfold enrichment in caveolin-1. In edematous lungs, cholesterol content and phospholipidic phosphorus increased by 15 and 40%, respectively. These data correlated with morphometric analysis of lungs fixed in situ by vascular perfusion with 2.5% glutaraldehyde, suggesting a relative increase in surface of luminal to interstitial front of the capillary endothelial cells, due to a convoluted luminal profile. In edematous lungs, the fraction of double-bound fatty acids increased in membrane lipids; moreover, the phosphatidylcholine/phosphatidylethanolamine and the cholesterol/phospholipid ratios decreased. These changes were consistent with the increase in fluorescence anisotropy of plasma membrane, indicating an increase in its fluidity. Data suggest that mechanical stimuli elicited by a modest (approximately 4%) increase in extravascular water cause marked changes in plasma membranes that may be of relevance in signal transduction and endothelial cell activation.
authors: Department of Experimental, Environmental Medicine and Biotechnology, University of Milano-Bicocca, Monza 20052, Italy.
authors: Paola
authors: P
authors: Palestini
authors: Chiara
authors: C
authors: Calvi
authors: Elena
authors: E
authors: Conforti
authors: Laura
authors: L
authors: Botto
authors: Carla
authors: C
authors: Fenoglio
authors: Giuseppe
authors: G
authors: Miserocchi
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002462:Cell Membrane / Q000737:chemistry* / Q000473:pathology; D002784:Cholesterol / Q000032:analysis; D004195:Disease Models, Animal; D005227:Fatty Acids / Q000032:analysis; D005454:Fluorescence Polarization; D008055:Lipids / Q000032:analysis; D008168:Lung / Q000737:chemistry / Q000201:enzymology / Q000473:pathology; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000378:metabolism / Q000473:pathology; D008560:Membrane Fluidity; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism; D010743:Phospholipids / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D011654:Pulmonary Edema / Q000150:complications / Q000378:metabolism / Q000473:pathology; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013499:Surface Properties
chemical_list: D005227:Fatty Acids; D008055:Lipids; D010743:Phospholipids; D010758:Phosphorus; D002784:Cholesterol; D019001:Nitric Oxide Synthase