Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells

Journal Article · Fri Mar 01 00:00:00 EST 1985 · Lab. Invest.; (United States)

OSTI ID:5779513

Atkins, F M; Friedman, M M; Metcalfe, D D

Incubation of (/sup 35/S)heparin-containing mast cell granules with cultured bovine endothelial cells was followed by the appearance of /sup 35/S-granule-associated radioactivity within the endothelial cells and a decrease in radioactivity in the extracellular fluid. These changes occurred during the first 24 hours of incubation and suggested ingestion of the mast cell granules by the endothelial cells. Periodic electron microscopic examination of the monolayers confirmed this hypothesis by demonstrating apposition of the granules to the plasmalemma of endothelial cells, which was followed by the engulfment of the granules by cytoplasmic projections. Under light microscopic examination, mast cell granules within endothelial cells then appeared to undergo degradation. The degradation of (/sup 35/S)heparin in mast cell granules was demonstrated by a decrease in the amount of intracellular (/sup 35/S)heparin proteoglycan after 24 hours and the appearance of free (/sup 35/S)sulfate in the extracellular compartment. Intact endothelial cells were more efficient at degrading (/sup 35/S)heparin than were cell lysates or cell supernatants. These data provide evidence of the ability of endothelial cells to ingest mast cell granules and degrade native heparin that is presented as a part of the mast cell granule.

• Research Organization: National Institute of Allergy and Infectious Diseases, Bethesda, MD
• OSTI ID: 5779513
• Journal Information: Lab. Invest.; (United States), Vol. 52:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HEPARIN
DECOMPOSITION
BIOCHEMISTRY
CATTLE
CYTOPLASM
ELECTRON MICROSCOPY
ENDOTHELIUM
LABELLED COMPOUNDS
MAST CELLS
RADIOACTIVITY
SULFUR 35
TRACER TECHNIQUES
AMINES
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
ANTICOAGULANTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
DRUGS
EVEN-ODD NUCLEI
HEMATOLOGIC AGENTS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MICROSCOPY
MUCOPOLYSACCHARIDES
NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYSACCHARIDES
RADIOISOTOPES
RUMINANTS
SACCHARIDES
SOMATIC CELLS
SULFUR ISOTOPES
TISSUES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques