An LC/MS/MS method for stable isotope dilution studies of ß-carotene bioavailability, bioconversion, and vitamin A status in humans.
J Lipid Res
; 55(2): 319-28, 2014 Feb.
Article
en En
| MEDLINE
| ID: mdl-24158962
ABSTRACT
Isotope dilution is currently the most accurate technique in humans to determine vitamin A status and bioavailability/bioconversion of provitamin A carotenoids such as ß-carotene. However, limits of MS detection, coupled with extensive isolation procedures, have hindered investigations of physiologically-relevant doses of stable isotopes in large intervention trials. Here, a sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) analytical method was developed to study the plasma response from coadministered oral doses of 2 mg [(13)C10]ß-carotene and 1 mg [(13)C10]retinyl acetate in human subjects over a 2 week period. A reverse phase C18 column and binary mobile phase solvent system separated ß-carotene, retinol, retinyl acetate, retinyl linoleate, retinyl palmitate/retinyl oleate, and retinyl stearate within a 7 min run time. Selected reaction monitoring of analytes was performed under atmospheric pressure chemical ionization in positive mode at m/z 537â321 and m/z 269â93 for respective [(12)C]ß-carotene and [(12)C] retinoids; m/z 547â330 and m/z 274â98 for [(13)C10]ß-carotene and [(13)C5] cleavage products; and m/z 279â100 for metabolites of [(13)C10]retinyl acetate. A single one-phase solvent extraction, with no saponification or purification steps, left retinyl esters intact for determination of intestinally-derived retinol in chylomicrons versus retinol from the liver bound to retinol binding protein. Coadministration of [(13)C10]retinyl acetate with [(13)C10]ß-carotene not only acts as a reference dose for inter-individual variations in absorption and chylomicron clearance rates, but also allows for simultaneous determination of an individual's vitamin A status.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Vitamina A
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Cromatografía Liquida
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Beta Caroteno
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Espectrometría de Masas en Tándem
Límite:
Adolescent
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Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Lipid Res
Año:
2014
Tipo del documento:
Article
País de afiliación:
Reino Unido