Degradation of pulmonary surfactant disaturated phosphatidylcholines by alveolar macrophages

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · J. Appl. Physiol.; (United States)

OSTI ID:6837623

Miles, P R; Ma, J Y; Bowman, L

Experiments were performed to determine whether rat pulmonary surfactant disaturated phosphatidylcholines (DSPC) are degraded by alveolar macrophages in vitro. When (3H)choline-labeled surfactant materials are incubated with unlabeled alveolar macrophages, approximately 40% of the labeled DSPC is broken down in 6 h. There is just a slight decrease in the specific activity of DSPC, which suggests that most products of degradation are not reincorporated into DSPC, at least during the 6-h incubation period. There is a time- and temperature-dependent association of surfactant DSPC with alveolar macrophages, and some of the cell-associated materials are released from the cell fragments after sonication. Association of surfactant with the cells precedes degradation. The breakdown of surfactant DSPC by intact alveolar macrophages lags behind that produced by sonicated cell preparations with disrupted cell membranes. These data and other information suggest that the surfactant materials are internalized by the cells, before the breakdown. The products of degradation probably include free choline and fatty acids, most of which appear in the extracellular fluid. The breakdown processes do not seem to depend on the physical form of the surfactant or on the presence of surfactant apoproteins. Incubation of the cells alone also results in disappearance of intracellular DSPC, some of which may be surfactant phospholipid taken up by the cells in vivo. These results indicate that alveolar macrophages can degrade surfactant DSPC and suggest that these cells may be involved in catabolism of pulmonary surfactant materials.

• Research Organization: Appalachian Laboratory for Occupational Safety and Health, Morgantown, WV (USA)
• OSTI ID: 6837623
• Journal Information: J. Appl. Physiol.; (United States), Journal Name: J. Appl. Physiol.; (United States) Vol. 64:6; ISSN JAPYA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMAL CELLS
ANIMALS
BIOLOGICAL FUNCTIONS
CELL CONSTITUENTS
CHOLINE
CONNECTIVE TISSUE CELLS
DRUGS
ESTERS
FUNCTIONS
HYDROXY COMPOUNDS
IN VITRO
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
LIPOSOMES
LIPOTROPIC FACTORS
MACROPHAGES
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
PHAGOCYTES
PHOSPHOLIPIDS
QUATERNARY COMPOUNDS
RATS
RODENTS
SOMATIC CELLS
SURFACTANTS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES