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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-11-25
pubmed:abstractText
The present study deals with an attempt to describe how the plasma cholesterol level is related to input into the plasma of cholesterol synthesized in the liver and in the intestine. It has previously been shown in our laboratory that, for a given absorption of alimentary cholesterol, the rat plasma cholesterol level decreases when internal secretion of cholesterol (cholesterol synthesized in the organs and poured into the plasma) increases. This relationship was established using rats in which the major source of cholesterol synthesis was the intestine. We used rats fed a cystine-enriched diet (5%) which was previously shown to increase cholesterolemia and internal secretion of cholesterol. It was first demonstrated that a significant positive linear correlation exists between individual values of cholesterolemia and those of internal secretion of cholesterol. Secondly, using [14C]acetate as the cholesterol precursor it was shown that ingestion of the cystine-enriched diet increased hepatic but not intestinal cholesterogenesis. Individual values of cholesterolemia were linearly correlated to those of [14C]acetate incorporation into the hepatic sterols. Results obtained by this method were validated by determining the 13C-labeling pattern of cholesterol synthesized de novo by the liver and the intestine after [13C]acetate infusion. Indeed, this labelling indicated that the dilution of exogenous acetyl-CoA in the liver was not changed by cystine feeding, whereas that in the intestine was enhanced. It is concluded that the plasma cholesterol level varies with internal cholesterol secretion, depending on the organ which determines the variations of this secretion: it decreases when intestinal cholesterogenesis increases, whereas it increases when hepatic cholesterogenesis increases. Finally, the use of [14C]acetate coupled with lipoprotein analysis in rats fed the cystine-enriched diet, in control rats and in rats fed a cholesterol-enriched diet, allowed a new linear correlation to be demonstrated: between cholesterol concentration in LDL2 (lipoproteins of density 1.040-1.063 g/ml) and [14C]acetate incorporation into liver sterols. Our results suggest that LDL2 are produced by the liver in relation to cholesterogenesis in this organ.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
921
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
522-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
A new relationship between cholesterolemia and cholesterol synthesis determined in rats fed an excess of cystine.
pubmed:affiliation
Laboratoire de Physiologie de la Nutrition, CNRS UA 646, Université de Paris-Sud, Orsay, France.
pubmed:publicationType
Journal Article