Simultaneous quantitative determination of deuterium- and carbon-13-labeled essential fatty acids in rat plasma

Autor: Yu Hong Lin, Robert J. Pawlosky, Norman Salem, Jr.
Jazyk: angličtina
Rok vydání: 2005
Předmět:
Zdroj: Journal of Lipid Research, Vol 46, Iss 9, Pp 1974-1982 (2005)
Druh dokumentu: article
ISSN: 0022-2275
DOI: 10.1194/jlr.M500128-JLR200
Popis: This study reports methods for the quantitative determination of stable isotope-labeled essential fatty acids (EFAs) as well as an experiment in which deuterium-labeled linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) were compared with those labeled with carbon-13 in rat plasma in vivo. Standard curves were constructed to compensate for concentration and plasma matrix effects. It was observed that endogenous pools of fatty acids had a greater suppressing effect on the measurements of 13C-U-labeled EFAs relative to those labeled with 2H5. Using these methods, the in vivo metabolism of orally administered deuterated-linolenate, 13C-U-labeled linolenate, deuterated-linoleate, and 13C-U-labeled linoleate was compared in adult rats (n = 11). There were no significant differences in the concentrations of the 2H versus 13C isotopomers of 18:2n-6, 18:3n-3, arachidonic acid (20:4n-6), and docosahexaenoic acid (22:6n-3) in rat plasma samples at 24 h after dosing.Thus, there appears to be little isotope effect for 2H5- versus 13C-U-labeled EFAs when the data are calculated using the conventional standard curves and corrected for endogenous fatty acid pool size and matrix effects.
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