A liquid chromatography/tandem mass spectrometry method for measuring the in vivo incorporation of plasma free fatty acids into intramyocellular ceramides in humans.
Rapid Commun Mass Spectrom
; 26(9): 1134-40, 2012 May 15.
Article
em En
| MEDLINE
| ID: mdl-22467464
ABSTRACT
RATIONALE Sphingolipids are important components of cell membranes that serve as cell signaling molecules; ceramide plays a central role in sphingolipid metabolism. De novo ceramide biosynthesis depends on fatty acid availability, but whether muscle uses circulating free fatty acids or pre-existing intracellular stores is unknown. Our goal was to develop a method to detect the incorporation of intravenously infused [U-(13)C]palmitate into intramyocellular ceramides. METHODS:
We used liquid chromatography/tandem mass spectrometry (LC/MS/MS) to measure the concentrations of different sphingolipid species and (13)C-isotopic enrichment of 160-ceramide. Chromatographic separation was performed using ultra-performance liquid chromatography. The analysis was performed on a triple quadrupole mass spectrometer using a positive ion electrospray ionization source with selected reaction monitoring (SRM).RESULTS:
The sphingolipids ions, except enriched ceramide, were monitored as [M+2+H](+). The [(13)C(16)]160-ceramide was monitored as [M+16+H](+). By monitoring two different transitions of the [(13)C(16)]160-ceramide (554/536 and 554/264) we could indirectly measure enrichment of the palmitate that is not a part of the sphingoid base. Concentration and enrichment could be measured using 20 mg of muscle obtained from volunteers receiving a low dose [U-(13)C]palmitate infusion.CONCLUSIONS:
LC/MS/MS can be used to detect the incorporation of plasma palmitate into muscle ceramides in humans, in vivo.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Palmitatos
/
Ceramidas
/
Cromatografia Líquida de Alta Pressão
/
Músculo Esquelético
/
Espectrometria de Massas em Tandem
Limite:
Humans
Idioma:
En
Revista:
Rapid Commun Mass Spectrom
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos