Hepatic metabolism of oxidatively modified apo E-free high-density lipoproteins.

Autor: DeLamatre JG; Department of Physiology, Louisiana State University Medical Center, New Orleans 70112, USA., Gabaldon DM, Arnold CS, Sarphie TG, Hornick CA
Jazyk: angličtina
Zdroj: Liver [Liver] 1998 Aug; Vol. 18 (4), pp. 264-71.
DOI: 10.1111/j.1600-0676.1998.tb00164.x
Abstrakt: Aims/background: The metabolism of rat apo E-free high-density lipoproteins (HDL) was contrasted with oxidatively modified apo E-free high-density lipoproteins (OX-HDL) in the rat hepatoma cell, Fu5AH.
Results: When 10-100 microg/ml [125I]-HDL or [125I]-OX-HDL were incubated with cells for 4 h at 37 degrees C, cellular uptake of oxidized lipoproteins was twice control. In contrast, protein degradation was equal. [125I]-HDL or [125I]-OX-HDL were incubated with the cells for 4 h followed by a 4 h chase with unlabeled HDL and OX-HDL, respectively. In these experiments, 80% of [125I]-HDL was resecreted from the cell within 30 min while 50% of [125I]-OX-HDL was retained by the cell after 2 h. Electron microscopy was used to determine if the OX-HDL was retained in lysosomes. Cells were incubated with gold-labeled OX-HDL, and lysosomes were stained with acid phosphatase. Gold-labeled OX-HDL was abundant in intracellular vesicles that were not reactive to acid phosphatase. However, vesicles with a high content of OX-HDL frequently stained positively for 3,3'-diaminobenzidine, a stain that reacts with catalase and is used to detect peroxisomes.
Conclusions: The present evidence indicates that the cellular metabolism of OX-HDL is different from that of unmodified HDL.
Databáze: MEDLINE
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