Effect of apolipoprotein E-free high density lipoproteins on cholesterol metabolism in cultured pig hepatocytes

Journal Article · Mon Oct 05 04:00:00 EDT 1987 · J. Biol. Chem.; (United States)

OSTI ID:5856004

Bachorik, P S; Virgil, D G; Kwiterovich, Jr, P O

We studied cholesterol synthesis from (/sup 14/C)acetate, cholesterol esterification from (/sup 14/C)oleate, and cellular cholesterol and cholesteryl ester levels after incubating cells with apoE-free high density lipoproteins (HDL) or low density lipoproteins (LDL). LDL suppressed synthesis by up to 60%, stimulated esterification by up to 280%, and increased cell cholesteryl ester content about 4-fold. Esterification increased within 2 h, but synthesis was not suppressed until after 6 h. ApoE-free HDL suppressed esterification by about 50% within 2 h. Cholesterol synthesis was changed very little within 6 h, unless esterification was maximally suppressed; synthesis was then stimulated about 4-fold. HDL lowered cellular unesterified cholesterol by 13-20% within 2 h and promoted the removal of newly synthesized cholesterol and cholesteryl esters. These changes were transient; by 24 h, both esterification and cellular unesterified cholesterol returned to control levels, and cholesteryl esters increased 2-3-fold. HDL core lipid was taken up selectively from /sup 125/I-labeled (/sup 3/H)cholesteryl ester- and ether-labeled HDL. LDL core lipid uptake was proportional to LDL apoprotein uptake. The findings suggest that 1) the cells respond initially to HDL or LDL with changes in esterification, and 2) HDL mediates both the removal of free cholesterol from the cell and the delivery of HDL cholesteryl esters to the cell.

• Research Organization: Johns Hopkins Univ. School of Medicine, Baltimore, MD
• OSTI ID: 5856004
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 262:28; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CELL CULTURES
CHEMICAL REACTIONS
CHOLESTEROL
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ESTERIFICATION
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIPIDS
LIPOPROTEINS
LIVER CELLS
MAMMALS
METABOLISM
MONOCARBOXYLIC ACIDS
NUCLEI
ODD-EVEN NUCLEI
OLEIC ACID
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SOMATIC CELLS
STEROIDS
STEROLS
SWINE
TRACER TECHNIQUES
VERTEBRATES