Nascent VLDL from liver perfusions of cynomolgus monkeys are preferentially enriched in RRR- compared with SRR-alpha-tocopherol: Studies using deuterated tocopherols

Journal Article · Sun Apr 01 00:00:00 EST 1990 · Journal of Lipid Research; (USA)

OSTI ID:7064068

Traber, M G; Rudel, L L; Burton, G W; Hughes, L; Ingold, K U; Kayden, H J ^[1]

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1. New York Univ. School of Medicine, NY (USA)

The transport and secretion of vitamin E in lipoproteins have been studied in cynomolgus monkeys fed tocopherols labeled with different amounts of deuterium. The animals were fed a single dose of vitamin E containing 60 mumol of each 2R,4'R,8'R-alpha-(5,7-(C2H3)2)tocopheryl acetate (d6-RRR-alpha-tocopheryl acetate; alpha-tocopherol with natural stereochemistry), 2S,4'R,8'R-alpha-5-(C2H3)tocopheryl acetate (d3-SRR-alpha-tocopheryl acetate; alpha-tocopherol with unnatural stereochemistry), and 2R,4'R,8'R-gamma-(3,4-2H)tocopherol (d2-RRR-gamma-tocopherol; gamma-tocopherol with natural stereochemistry). Chylomicrons, as well as the other plasma lipoproteins, contained equal concentrations of all three tocopherols at the earliest time points after feeding suggesting that all three tocopherols were absorbed equally. At later times plasma lipoproteins became preferentially enriched in d6-RRR-alpha-tocopherol. This is likely to be due to hepatic secretion of VLDL (very low density lipoproteins) and other lipoproteins, which were enriched in d6-RRR-alpha-tocopherol, as demonstrated in the lipoproteins isolated from perfused livers that had been obtained 24 h following the administration of the deuterated tocopherols. Taken together these data demonstrate that the liver, not the intestine, is the likely site of discrimination between tocopherol isomers and that the liver secretes nascent lipoproteins preferentially enriched in d6-RRR-alpha-tocopherol.

• OSTI ID: 7064068
• Journal Information: Journal of Lipid Research; (USA), Vol. 31:4; ISSN 0022-2275
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
LIPOPROTEINS
SECRETION
VITAMIN E
MEMBRANE TRANSPORT
CHYLOMICRONS
DEUTERIUM
LIVER
MONKEYS
PERFUSED ORGANS
STEREOCHEMISTRY
ANIMALS
BODY
DIGESTIVE SYSTEM
GLANDS
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAMMALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PRIMATES
PROTEINS
STABLE ISOTOPES
VERTEBRATES
VITAMINS
550201* - Biochemistry- Tracer Techniques