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标题：Compartmental modeling to quantify {alpha}-linolenic acid conversion after longer term intake of multiple tracer boluses
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作者：Goyens, Petra L. L. ; Spilker, Mary E. ; Zock, Peter L. 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2005
卷号：46
期号：07
页码：1474-1483
DOI：10.1194/jlr.M400514-JLR200
出版社：American Society for Biochemistry and Molecular Biology
摘要：To estimate in vivo ${alpha}$ -linolenic acid (ALA; C18:3n-3) conversion,29 healthy subjects consumed for 28 days a diet providing 7%of energy from linoleic acid (C18:2n-6) and 0.4% from ALA. Onday 19, subjects received a single bolus of 30 mg of uniformlylabeled [¹³C]ALA and for the next 8 days 10 mg twice daily.Fasting plasma phospholipid concentrations of ¹²C- and ¹³C-labeledALA, eicosapentaenoic acid (EPA; C20:5n-3), docosapentaenoicacid (DPA; C22:5n-3), and docosahexaenoic acid (DHA; C22:6n-3)were determined on days 19, 21, 23, 26, 27, and 28. To estimatehepatic conversion of n-3 fatty acids, a tracer model was developedbased on the averaged ¹³C data of the participants. A similartracee model was solved using the averaged ¹²C values, the kineticparameters derived from the tracer model, and mean ALA consumption.ALA incorporation into plasma phospholipids was estimated bysolving both models simultaneously. It was found that nearly7% of dietary ALA was incorporated into plasma phospholipids.From this pool, 99.8% was converted into EPA and 1% was convertedinto DPA and subsequently into DHA. The limited incorporation of dietary ALA into the hepatic phospholipidpool contributes to the low hepatic conversion of ALA into EPA.A low conversion of ALA-derived EPA into DPA might be an additionalobstacle for DHA synthesis. Abbreviations: ALA, ${alpha}$ -linolenic acid (C18:3n-3); AUC, area under the curve; CE, cholesteryl ester; DHA, docosahexaenoic acid (C22:6n-3); DPA, docosapentaenoic acid (C22:5n-3); En%, percent of energy; EPA, eicosapentaenoic acid (C20:5n-3); FAME, fatty acid methyl ester; LCPUFA, long-chain polyunsaturated fatty acid; TG, triacylglycerol; [U-¹³C]ALA, uniformly labeled [¹³C] ${alpha}$ -linolenic acid Supplementary key words desaturation • elongation • metabolism • stable isotopes • human