Comparison of the metabolic effects of chylomicrons and their remnants on isolated hepatocytes

Takahide Nomura, Elizabeth A. Irving, Robert Harris

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A comparison was made between the effects of chylomicrons and chylomicron remnants on metabolic processes of isolated hepatocytes. Since isolated triacylglycerol-rich lipoproteins are contaminated with nonesterified fatty acids, control incubations were conducted with an amount of fatty acid equivalent to the contaminating fatty acids present in the chylomicrons and the remnant preparations, respectively. Chylomicron remnants, produced in vitro by incubation of chylomicrons in postheparin rat plasma, caused marked inhibition of glycolysis, fatty acid synthesis, and cholesterol synthesis, along with marked stimulation of ketogenesis. These effects were traced to the release of nonesterified fatty acids from these remnant particles as a consequence of contamination with lipoprotein lipase, picked up by the particles during the incubation with rat plasma. Fatty acids inhibit glycolysis, cholesterol, and fatty acid synthesis, but enhance ketone body formation by isolated hepatocytes. Chylomicrons and remnants prepared in vivo by the injection of chylomicrons into functionally hepatectomized rats were not contaminated with lipoprotein lipase and did not inhibit glycolysis and cholesterol synthesis nor increase ketone body formation. These lipoprotein particles did, however, cause significant inhibition of fatty acid synthesis, with the chylomicrons being more effective on a protein basis than the remnants produced in vivo. The mechanism responsible for the inhibition of fatty acid synthesis by chylomicrons and remnants prepared in vivo remains to be resolved.

Original languageEnglish
Pages (from-to)211-221
Number of pages11
JournalArchives of Biochemistry and Biophysics
Volume211
Issue number1
DOIs
StatePublished - Oct 1 1981

Fingerprint

Chylomicron Remnants
Hepatocytes
Fatty Acids
Chylomicrons
Glycolysis
Rats
Ketone Bodies
Lipoprotein Lipase
Cholesterol
Nonesterified Fatty Acids
Lipoproteins
Plasmas
Triglycerides
Contamination
Injections

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

Comparison of the metabolic effects of chylomicrons and their remnants on isolated hepatocytes. / Nomura, Takahide; Irving, Elizabeth A.; Harris, Robert.

In: Archives of Biochemistry and Biophysics, Vol. 211, No. 1, 01.10.1981, p. 211-221.

Research output: Contribution to journalArticle

@article{fc18469af5ee45d0a2741a248cd61cf1,
title = "Comparison of the metabolic effects of chylomicrons and their remnants on isolated hepatocytes",
abstract = "A comparison was made between the effects of chylomicrons and chylomicron remnants on metabolic processes of isolated hepatocytes. Since isolated triacylglycerol-rich lipoproteins are contaminated with nonesterified fatty acids, control incubations were conducted with an amount of fatty acid equivalent to the contaminating fatty acids present in the chylomicrons and the remnant preparations, respectively. Chylomicron remnants, produced in vitro by incubation of chylomicrons in postheparin rat plasma, caused marked inhibition of glycolysis, fatty acid synthesis, and cholesterol synthesis, along with marked stimulation of ketogenesis. These effects were traced to the release of nonesterified fatty acids from these remnant particles as a consequence of contamination with lipoprotein lipase, picked up by the particles during the incubation with rat plasma. Fatty acids inhibit glycolysis, cholesterol, and fatty acid synthesis, but enhance ketone body formation by isolated hepatocytes. Chylomicrons and remnants prepared in vivo by the injection of chylomicrons into functionally hepatectomized rats were not contaminated with lipoprotein lipase and did not inhibit glycolysis and cholesterol synthesis nor increase ketone body formation. These lipoprotein particles did, however, cause significant inhibition of fatty acid synthesis, with the chylomicrons being more effective on a protein basis than the remnants produced in vivo. The mechanism responsible for the inhibition of fatty acid synthesis by chylomicrons and remnants prepared in vivo remains to be resolved.",
author = "Takahide Nomura and Irving, {Elizabeth A.} and Robert Harris",
year = "1981",
month = "10",
day = "1",
doi = "10.1016/0003-9861(81)90446-X",
language = "English",
volume = "211",
pages = "211--221",
journal = "Archives of Biochemistry and Biophysics",
issn = "0003-9861",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Comparison of the metabolic effects of chylomicrons and their remnants on isolated hepatocytes

AU - Nomura, Takahide

AU - Irving, Elizabeth A.

AU - Harris, Robert

PY - 1981/10/1

Y1 - 1981/10/1

N2 - A comparison was made between the effects of chylomicrons and chylomicron remnants on metabolic processes of isolated hepatocytes. Since isolated triacylglycerol-rich lipoproteins are contaminated with nonesterified fatty acids, control incubations were conducted with an amount of fatty acid equivalent to the contaminating fatty acids present in the chylomicrons and the remnant preparations, respectively. Chylomicron remnants, produced in vitro by incubation of chylomicrons in postheparin rat plasma, caused marked inhibition of glycolysis, fatty acid synthesis, and cholesterol synthesis, along with marked stimulation of ketogenesis. These effects were traced to the release of nonesterified fatty acids from these remnant particles as a consequence of contamination with lipoprotein lipase, picked up by the particles during the incubation with rat plasma. Fatty acids inhibit glycolysis, cholesterol, and fatty acid synthesis, but enhance ketone body formation by isolated hepatocytes. Chylomicrons and remnants prepared in vivo by the injection of chylomicrons into functionally hepatectomized rats were not contaminated with lipoprotein lipase and did not inhibit glycolysis and cholesterol synthesis nor increase ketone body formation. These lipoprotein particles did, however, cause significant inhibition of fatty acid synthesis, with the chylomicrons being more effective on a protein basis than the remnants produced in vivo. The mechanism responsible for the inhibition of fatty acid synthesis by chylomicrons and remnants prepared in vivo remains to be resolved.

AB - A comparison was made between the effects of chylomicrons and chylomicron remnants on metabolic processes of isolated hepatocytes. Since isolated triacylglycerol-rich lipoproteins are contaminated with nonesterified fatty acids, control incubations were conducted with an amount of fatty acid equivalent to the contaminating fatty acids present in the chylomicrons and the remnant preparations, respectively. Chylomicron remnants, produced in vitro by incubation of chylomicrons in postheparin rat plasma, caused marked inhibition of glycolysis, fatty acid synthesis, and cholesterol synthesis, along with marked stimulation of ketogenesis. These effects were traced to the release of nonesterified fatty acids from these remnant particles as a consequence of contamination with lipoprotein lipase, picked up by the particles during the incubation with rat plasma. Fatty acids inhibit glycolysis, cholesterol, and fatty acid synthesis, but enhance ketone body formation by isolated hepatocytes. Chylomicrons and remnants prepared in vivo by the injection of chylomicrons into functionally hepatectomized rats were not contaminated with lipoprotein lipase and did not inhibit glycolysis and cholesterol synthesis nor increase ketone body formation. These lipoprotein particles did, however, cause significant inhibition of fatty acid synthesis, with the chylomicrons being more effective on a protein basis than the remnants produced in vivo. The mechanism responsible for the inhibition of fatty acid synthesis by chylomicrons and remnants prepared in vivo remains to be resolved.

UR - http://www.scopus.com/inward/record.url?scp=0019844891&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019844891&partnerID=8YFLogxK

U2 - 10.1016/0003-9861(81)90446-X

DO - 10.1016/0003-9861(81)90446-X

M3 - Article

C2 - 7305366

AN - SCOPUS:0019844891

VL - 211

SP - 211

EP - 221

JO - Archives of Biochemistry and Biophysics

JF - Archives of Biochemistry and Biophysics

SN - 0003-9861

IS - 1

ER -