Document Detail


Catabolism of the apoprotein of low density lipoproteins by the isolated perfused rat liver.
MedLine Citation:
PMID:  209115     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Isolated rat livers were perfused for 4 hours in a recirculating system containing washed rat erythrocytes. Biologically screened, radioiodinated low density lipoproteins (1.030 < d < 1.055 g/ml) were added to the perfusate with different amounts of whole serum to supply unlabeled rat low density lipoproteins. Apolipoprotein B contained 90% of the bound (131)I, other apolipoproteins contained 4%, and lipids contained the remainder. The fraction of apolipoprotein mass degraded during the perfusion was quantified by the linear increment of non-protein-bound radioiodine in the perfusate, corrected for the increment observed during recirculation of the perfusate in the absence of a liver. The fractional catabolic rate ranged from 0.3 to 1.7%/hr in seven experiments and was inversely related to the size of perfusate pool of low density apolipoprotein. The catabolic rate of low density apolipoprotein (fractional catabolic rate x pool size) in four livers, in which the concentration of rat low density lipoproteins was 50-100% of that present in intact rats, was 5.3 +/- 2.7 micro g hr(-1) (mean +/- SD). Similar results were obtained with human low density lipoproteins. These rates were compared with catabolic rates for the apoprotein of rat low density lipoproteins in intact animals. Fractional catabolic rate in vivo, obtained by multi-compartmental analysis of the disappearance curve of (131)I-labeled low density apolipoprotein from blood plasma, was 15.2 +/- 3.1% hr(-1) (mean +/- SD). Total catabolic rate in vivo (fractional catabolic rate x intravascular pool of low density apolipoprotein) was 76 +/- 14 micro g hr(-1) (mean +/- SD). The results suggest that only a small fraction of low density apolipoprotein mass in rats is degraded by the liver.
Authors:
G Sigurdsson; S P Noel; R J Havel
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of lipid research     Volume:  19     ISSN:  0022-2275     ISO Abbreviation:  J. Lipid Res.     Publication Date:  1978 Jul 
Date Detail:
Created Date:  1978-09-30     Completed Date:  1978-09-30     Revised Date:  2007-03-23    
Medline Journal Info:
Nlm Unique ID:  0376606     Medline TA:  J Lipid Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  628-34     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Animals
Apolipoproteins / blood,  metabolism*
Iodine Radioisotopes
Isotope Labeling
Lipoproteins, LDL / blood,  metabolism*
Liver / metabolism*
Male
Perfusion
Rats
Chemical
Reg. No./Substance:
0/Apolipoproteins; 0/Iodine Radioisotopes; 0/Lipoproteins, LDL

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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