Linked Life Data

7213773

Source:http://linkedlifedata.com/resource/pubmed/id/7213773

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1981-6-25
pubmed:abstractText
Lipoproteins in the three major density classes were isolated from the medium of cultured rat hepatocytes incubated in the absence of serum for periods ranging from 1 to 48 h. De novo synthesis was suggested by the cycloheximide-sensitive incorporation of [3H]leucine into the apolipoproteins of the secreted lipoproteins. Hepatocyte d less than 1.006 and d 1.006-1.063 g/ml lipoproteins were similar to plasma very low density lipoprotein (VLDL) and low density lipoprotein (LDL), respectively, in chemical composition, morphology and apolipoprotein distribution. The isolation of plasma-like d 1.006-1.063 g/ml particles is evidence for the hepatic origin of rat LDL; however, whether these particles are synthesized directly or result from catabolism of secreted VLDL has not been determined. Spherical d 1.063-1.21 g/ml particles containing predominantly apolipoprotein A-I were isolated from the media. In contrast to plasma high density lipoprotein (HDL) the hepatocyte particles contained significant concentrations of triacylglycerol and apolipoproteins of Mr greater than 100,000 and lacked apolipoprotein A-IV. The pattern of lipoprotein secretion was related to the time of incubation. After incubation for 1, 3 and 6.5 h, VLDL comprised approx. 56% of the total lipoprotein mass, LDL 20% and HDL 24%. After 17 and 48 h the VLDL concentration was greatly reduced (approx. 20% of the total mass) while LDL and HDL concentrations were increased (33 and 47% of the total, respectively). Exogenous sodium oleate resulted in a concentration-dependent stimulation of VLDL synthesis at longer incubation periods. The triacylglycerol content of the secreted LDL fraction was also significantly increased following sodium oleate addition and there was an increased number of 425-650 A particles present, which may represent catabolic products of VLDL. Hepatocyte monolayers which can be maintained in serum-free media for extended period should be useful for studying regulation of hepatic metabolism of the three major lipoprotein classes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
663
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
83-98
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Time-related changes in the synthesis and secretion of very low density, low density and high density lipoproteins by cultured rat hepatocytes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.