Uptake and processing of remnants of chylomicrons and very low density lipoproteins by rat liver

Journal Article · Thu Nov 01 04:00:00 EST 1984 · J. Lipid Res.; (United States)

OSTI ID:5709972

Jones, A L; Hradek, G T; Hornick, C; Renaud, G; Windler, E E; Havel, R J

In the rat, chylomicron remnants and very low density lipoprotein (VLDL) remnants are taken up into the liver by high affinity processes and appear to undergo degradation by lysosomes. The relationship of this catabolic process to the known pathways of uptake and degradation of low density lipoproteins (LDL) and the involvement of nonparenchymal cells are addressed in these studies. The authors have utilized both light and electron microscopic radioautography to determine whether the pathway of intracellular transport and catabolism resembles that established for LDL in hepatocytes. Radioiodinated plasma VLDL remnants and lymph chylomicron remnants were injected into femoral veins of rats and the livers were fixed by perfusion 3 to 30 minutes later. Quantitative light microscopic radioautography showed little or no accumulation of grains over Kupffer cells. Electromicroscopic radioautography confirmed these observations and, in addition, demonstrated that very few grains were associated with endothelial cells. The processing of the remnant particles closely resembled that of LDL. Following an initial association of grains with the parenchymal cell plasma membrane, frequently in regions in close proximity to clathrin-coated endocytic pits, the grains were found in endocytic vesicles just beneath the plasma membrane. By 15 minutes the grains were found over multivesicular bodies located in the Golgi-lysosome region of the cell. Thirty minutes after injection, radioautographic grains began to be associated with secondary lysosomes.

• Research Organization: Veterans Administration Medical Center, San Francisco, CA
• OSTI ID: 5709972
• Journal Information: J. Lipid Res.; (United States), Journal Name: J. Lipid Res.; (United States) Vol. 25:11; ISSN JLPRA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMAL TISSUES
ANIMALS
AUTORADIOGRAPHY
BIOLOGICAL PATHWAYS
BODY
CATABOLISM
CELL CONSTITUENTS
CELL MEMBRANES
CHYLOMICRONS
DIGESTIVE SYSTEM
ENDOTHELIUM
GLANDS
IODINE ISOTOPES
ISOTOPES
LIPIDS
LIPOPROTEINS
LIVER
LYSOSOMES
MAMMALS
MEMBRANES
METABOLISM
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PROTEINS
RATS
RODENTS
TISSUES
UPTAKE
VERTEBRATES