Degradation of rat pulmonary surfactant disaturated phosphatidylcholines (DSPC) by alveolar macrophages

Conference · Wed Mar 05 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6935106

Miles, P R; Bowman, L

Experiments were carried out to determine the fate of pulmonary surfactant DSPC when it is incubated in vitro with alveolar macrophages. Rats were injected (i.v.) with /sup 3/H-choline, sacrificed 22 hours later, and surfactant materials (sam) containing labeled DSPC were obtained by lung lavage and purified with NaBr density gradients. The sam was incubated in phosphate-buffered medium (containing 1.8 mM Ca/sup 2 +/ and 1.0 mM Mg/sup 2 +/) with alveolar macrophages from unlabeled animals. During incubation with cells for six hours, the labeled DSPC disappears along a time course which is most rapid between two and four hours. The labeled sam DSPC does not disappear when incubated without cells. A plot of the amount of DSPC broken down vs the sam DSPC concentration indicates that the process displays saturation kinetics. The specific activity of the DSPC in the incubation mixture does not change over six hours, suggesting that the breakdown products are not reutilized by the cells, at least during this time period. All of the label which disappears from the DSPC appears as water-soluble choline products. No lysophosphatidylcholines are formed. When the cells are incubated with dipalmitoylphosphatidylcholine (DPPC) vesicles, there is degradation of the DPPC which is approximately 50% of the breakdown which occurs with sam DSPC. These results suggest that surfactant DSPC can be degraded by alveolar macrophages.

• Research Organization: West Virginia Univ., Morgantown
• OSTI ID: 6935106
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:4
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMAL CELLS
ANIMALS
BODY
CHOLINE
CONNECTIVE TISSUE CELLS
DRUGS
ESTERS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
LIPOTROPIC FACTORS
LUNGS
MACROPHAGES
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHAGOCYTES
PHOSPHOLIPIDS
QUATERNARY COMPOUNDS
RATS
RESPIRATORY SYSTEM
RODENTS
SOMATIC CELLS
SURFACTANTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES