Metabolism of lipoproteins by human fetal hepatocytes

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Abstract

The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 μg low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [125I]iodo-LDL and [125I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [125I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [125I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues.

Original languageEnglish (US)
Pages (from-to)1338-1344
Number of pages7
JournalAmerican Journal of Obstetrics and Gynecology
Volume157
Issue number6
StatePublished - 1987

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LDL Lipoproteins
Lipoproteins
Hepatocytes
HDL Lipoproteins
LDL Receptors
Liver
Iodine
Atherosclerosis
Membrane Proteins
Proteins
Membranes
iodo-LDL

ASJC Scopus subject areas

  • Medicine(all)
  • Obstetrics and Gynecology

Cite this

Metabolism of lipoproteins by human fetal hepatocytes. / Carr, B. R.

In: American Journal of Obstetrics and Gynecology, Vol. 157, No. 6, 1987, p. 1338-1344.

Research output: Contribution to journalArticle

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