Metabolism of triglyceride-rich nascent rat hepatic high density lipoproteins
- Medical College of Pennsylvania, Philadelphia (USA)
Nascent high density lipoprotein (HDL) and nascent very low density lipoprotein (VLDL) were isolated from rat livers that had been perfused with (3H)glycerol to label the triglyceride. When injected into intact rats, the labeled HDL-triglyceride disappeared as rapidly as the VLDL-triglyceride, with only 10% of the injected label remaining in the plasma after 30 min. The protein moiety of nascent HDL was labeled with (35S)methionine in a similar fashion and the labeled nascent HDL was separated into nonretained (NR) and retained (R) fractions by heparin-Sepharose affinity chromatography. When injected into rats, 55% of the injected label in nascent fraction NR and 72% of that in nascent fraction R was recovered from plasma at 30 min, compared to only 10% of the triglyceride label from unfractionated nascent HDL, indicating dissociation of triglyceride and apolipoprotein clearance. The plasma decay curves for both triglyceride and protein were biexponential. By 5 min, 15% of the 35S label remaining in plasma represented apoE and apoC that had been transferred from nascent HDL fractions NR and R to the d less than 1.063 g/ml fraction of plasma. Plasma HDL was labeled in vivo with (35S)methionine, separated into fractions NR and R, and the clearance of the two plasma HDL fractions was compared with that of the corresponding nascent HDL fractions. Except for a faster rate of removal of the nascent HDL fractions during the first 5 min, the serum decay curves were very similar.
- OSTI ID:
- 5159841
- Journal Information:
- Journal of Lipid Research; (USA), Journal Name: Journal of Lipid Research; (USA) Vol. 30:7; ISSN JLPRA; ISSN 0022-2275
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CHROMATOGRAPHY
CLEARANCE
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DRUGS
ESTERS
EVEN-ODD NUCLEI
GLANDS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPIDS
LIPOPROTEINS
LIPOTROPIC FACTORS
LIVER
MAMMALS
METABOLISM
METHIONINE
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PERFUSED ORGANS
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SEPARATION PROCESSES
SULFUR 35
SULFUR ISOTOPES
TRACER TECHNIQUES
TRIGLYCERIDES
TRITIUM COMPOUNDS
VERTEBRATES