A feasibility study quantifying in vivo human alpha-tocopherol metabolism.

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Abstract Text:

Andrew J Clifford,Fabiana F de Moura,Charlene C Ho,Jennifer C Chuang,Jennifer Follett,James G Fadel,Janet A Novotny,

BACKGROUND: Quantitation of human vitamin E metabolism is incomplete, so we quantified RRR- and all-rac-alpha-tocopherol metabolism in an adult. OBJECTIVE: The objective of the study was to quantify and interpret in vivo human vitamin E metabolism. DESIGN: A man was given an oral dose of 0.001821 micromol [5-14CH3]RRR-alpha-tocopheryl acetate (with 101.5 nCi 14C), and its fate in plasma, plasma lipoproteins, urine, and feces was measured over time. Data were analyzed and interpreted by using kinetic modeling. The protocol was repeated later with 0.001667 micromol [5-14CH3]all-rac-alpha-tocopheryl acetate (with 99.98 nCi 14C). RESULTS: RRR-alpha-tocopheryl acetate and all-rac-alpha-tocopheryl acetate were absorbed equally well (fractional absorption: approximately 0.775). The main route of elimination was urine, and approximately 90% of the absorbed dose was alpha-2(2'-carboxyethyl)-6-hydroxychroman. Whereas 93.8% of RRR-alpha-tocopherol flow to liver kinetic pool B from plasma was returned to plasma, only 80% of the flow of all-rac-alpha-tocopherol returned to plasma; the difference (14%) was degraded and eliminated. Thus, for newly digested alpha-tocopherol, the all-rac form is preferentially degraded and eliminated over the RRR form. Respective residence times in liver kinetic pool A and plasma for RRR-alpha-tocopherol were 1.16 and 2.19 times as long as those for all-rac-alpha-tocopherol. Model-estimated distributions of plasma alpha-tocopherol, extrahepatic tissue alpha-tocopherol, and liver kinetic pool B for RRR-alpha-tocopherol were, respectively, 6.77, 2.71, and 3.91 times as great as those for all-rac-alpha-tocopherol. Of the lipoproteins, HDL had the lowest 14C enrichment. Liver had 2 kinetically distinct alpha-tocopherol pools. CONCLUSIONS: Both isomers were well absorbed; all-rac-alpha-tocopherol was preferentially degraded and eliminated in urine, the major route. RRR-alpha-tocopherol had a longer residence time and larger distribution than did all-rac-alpha-tocopherol. Liver had 2 distinct alpha-tocopherol pools. The model is a hypothesis, its estimates are model-dependent, and it encourages further testing.

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Publishing Authors By Initials

AJ Clifford,FF de Moura,CC Ho,JC Chuang,J Follett,JG Fadel,JA Novotny,

For similar heterocyclic compounds: heterocyclic compounds, 2-ring: benzopyrans: vitamin e: tocopherols: alpha-tocopherol research abstracts see: heterocyclic compounds: heterocyclic compounds, 2-ring: benzopyrans: vitamin e: tocopherols: alpha-tocopherol research

PUBMED ID PMID:

MEDLINE DATE:

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Journal Published:

PUBLICATION TYPE: Research Support, U.S. Gov't,

Journal: The American journal of clinical nutrition

VOLUME: 84

Page Numbers: 1430-41

Journal Abbreviation: Am. J. Clin. Nutr.

ISSN: 0002-9165

DAY: 3

MONTH: Dec

YEAR: 2006

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 376027

A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Keywords Mesh Terms:

KEYWORDS: alpha-Tocopherol

MESH TERMS: urine

Chemical & Substance for Abstract: A feasibility study quantifying in vivo human alpha-tocopherol metabolism. Information

Substance Name: tocopherol acetate

Registry Number: 7695-91-2

Grant and Affiliation Information for A feasibility study quantifying in vivo human alpha-tocopherol metabolism.

AFFILIATION: Department of Nutrition, University of California, Davis, Davis, CA 5616-8669, USA. ajclifford@ucdavis.edu

Country: United States

AGENCY: United States NCRR

GRANT: RR13461

ACRONYM: RR

MEDLINETA: Am J Clin Nutr

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

A feasibility study quantifying in vivo human alpha-tocopherol metabolism Related Publications

• A feasibility study quantifying in vivo human alpha-tocopherol metabolism.
• Addressing smoking cessation in tuberculosis control.
• Alkaloids from Rauwolfia salicifolia.
• Alkaloids from Strempeliopsis strempelioides.
• Alterations in the serum glycome due to metastatic prostate cancer.
• Anthocyanins present in selected tropical fruits: acerola, jambolão, jussara, and guajiru.
• Arthrogryposis associated with connatal Pelizaeus-Merzbacher disease: case report.
• Biochemical and environmental applications of microcolumn liquid and supercritical fluid chromatography.
• Comparative glycomic mapping through quantitative permethylation and stable-isotope labeling.
• Conjugate field and fluctuation-dissipation relation for the dynamic phase transition in the two-dimensional kinetic Ising model.
• Conservative treatment of clavicular fractures.
• Creating effective advisory boards for schools of nursing.
• Determination of salsolinol and related catecholamines through on-line preconcentration and liquid chromatography/atmospheric pressure photoionization mass spectrometry.
• Effective wavelength scaling for optical antennas.
• Efficacy and Tolerability of a Fixed Combination of Cinnarizine and Dimenhydrinate versus Betahistine in the Treatment of Otogenic Vertigo : A Double-Blind, Randomised Clinical Study.
• Extracting knowledge on the links between the water body stressors and biotic integrity.
• High-sensitivity profiling of glycoproteins from human blood serum through multiple-lectin affinity chromatography and liquid chromatography/tandem mass spectrometry.
• Improved collision-induced dissociation analysis of peptides by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry through 3-sulfobenzoic acid succinimidyl ester labeling.
• It'S all in the history.
• Mice respond differently to urine and its major volatile constituents from male and female ferrets.
• Perceptions of tobacco advertising and marketing that might lead to smoking initiation among Chinese high school girls.
• Semiautomated high-sensitivity profiling of human blood serum glycoproteins through lectin preconcentration and multidimensional chromatography/tandem mass spectrometry.
• Surface plasmon interference excited by tightly focused laser beams.
• [Lycopene therapy in male infertility]
• [Not Available.]
• [Not Available.]
• [Not Available.]
• [Not Available.]
• [Not Available.]
• [Not Available.]