Measurement of very low density and low density lipoprotein apolipoprotein (Apo) B-100 and high density lipoprotein Apo A-I production in human subjects using deuterated leucine. Effect of fasting and feeding

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Journal of Clinical Investigation; (USA)

DOI:https://doi.org/10.1172/JCI114507· OSTI ID:6921413

Cohn, J S; Wagner, D A; Cohn, S D; Millar, J S; Schaefer, E J ^[1]

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1. Tufts Univ., Boston, MA (USA)

Six normolipidemic male subjects, after an 8-h overnight fast, were given a bolus injection and then a 15-h constant intravenous infusion of (D3)L-leucine. Subjects were studied in the fasted state and on a second occasion in the fed state (small, physiological meals were given every hour for 15 h). Apolipoproteins were isolated by preparative gradient gel electrophoresis from plasma lipoproteins separated by sequential ultracentrifugation. Incorporation of (D3)L-leucine into apolipoproteins was monitored by negative ionization, gas chromatography-mass spectrometry. Production rates were determined by multiplying plasma apolipoprotein pool sizes by fractional production rates calculated as the rate of isotopic enrichment (IE) of each protein as a fraction of IE achieved by VLDL (d less than 1.006 g/ml) apo B-100 at plateau. VLDL apo B-100 production was greater, and LDL (1.019 less than d less than 1.063 g/ml) apo B-100 production was less in the fed compared with the fasted state (9.9 +/- 1.7 vs. 6.4 +/- 1.7 mg/kg per d, P less than 0.01, and 8.9 +/- 1.2 vs. 13.1 +/- 1.2 mg/kg per d, P less than 0.05, respectively). No mean change was observed in high density lipoprotein apo A-I production. We conclude that: (a) this stable isotope, endogenous-labeling technique, for the first time allows for the in vivo measurement of apolipoprotein production in the fasted and fed state; and (b) since LDL apo B-100 production was greater than VLDL apo B-100 production in the fasted state, this study provides in vivo evidence that LDL apo B-100 can be produced independently of VLDL apo B-100 in normolipidemic subjects.

• OSTI ID: 6921413
• Journal Information: Journal of Clinical Investigation; (USA), Journal Name: Journal of Clinical Investigation; (USA) Vol. 85:3; ISSN 0021-9738; ISSN JCINA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
APOLIPOPROTEINS
BIOSYNTHESIS
CARBOXYLIC ACIDS
CENTRIFUGATION
CHOLESTEROL
CHROMATOGRAPHY
DEUTERIUM
ELECTROPHORESIS
ESTERS
FASTING
GAS CHROMATOGRAPHY
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLING
LEUCINE
LIGHT NUCLEI
LIPIDS
LIPOPROTEINS
MAMMALS
MAN
MASS SPECTROSCOPY
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PRIMATES
PROTEINS
SEPARATION PROCESSES
SPECTROSCOPY
STABLE ISOTOPES
STEROIDS
STEROLS
SYNTHESIS
TRACER TECHNIQUES
TRIGLYCERIDES
ULTRACENTRIFUGATION
VERTEBRATES