Compartmental modeling to quantify alpha-linolenic acid conversion after longer term intake of multiple tracer boluses

@article{citeulike:990167, abstract = {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. On day 19, subjects received a single bolus of 30 mg of uniformly labeled [13C]ALA and for the next 8 days 10 mg twice daily. Fasting plasma phospholipid concentrations of 12C- and 13C-labeled ALA, eicosapentaenoic acid (EPA; C20:5n-3), docosapentaenoic acid (DPA; C22:5n-3), and docosahexaenoic acid (DHA; C22:6n-3) were determined on days 19, 21, 23, 26, 27, and 28. To estimate hepatic conversion of n-3 fatty acids, a tracer model was developed based on the averaged 13C data of the participants. A similar tracee model was solved using the averaged 12C values, the kinetic parameters derived from the tracer model, and mean ALA consumption. ALA incorporation into plasma phospholipids was estimated by solving both models simultaneously. It was found that nearly 7\% of dietary ALA was incorporated into plasma phospholipids. From this pool, 99.8\% was converted into EPA and 1\% was converted into DPA and subsequently into DHA. The limited incorporation of dietary ALA into the hepatic phospholipid pool contributes to the low hepatic conversion of ALA into EPA. A low conversion of ALA-derived EPA into DPA might be an additional obstacle for DHA synthesis. 10.1194/jlr.M400514-JLR200}, author = {Goyens, Petra L. and Spilker, Mary E. and Zock, Peter L. and Katan, Martijn B. and Mensink, Ronald P. }, citeulike-article-id = {990167}, doi = {http://dx.doi.org/10.1194/jlr.M400514}, journal = {J. Lipid Res.}, keywords = {diet, health, omega3}, month = {July}, number = {7}, pages = {1474--1483}, posted-at = {2006-12-12 21:29:19}, priority = {5}, title = {Compartmental modeling to quantify {alpha}-linolenic acid conversion after longer term intake of multiple tracer boluses}, url = {http://dx.doi.org/10.1194/jlr.M400514}, volume = {46}, year = {2005} }

TY - JOUR ID - citeulike:990167 L3 - citeulike-article-id:990167 TI - Compartmental modeling to quantify {alpha}-linolenic acid conversion after longer term intake of multiple tracer boluses JF - J. Lipid Res. VL - 46 IS - 7 SP - 1474 EP - 1483 N2 - 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. On day 19, subjects received a single bolus of 30 mg of uniformly labeled [13C]ALA and for the next 8 days 10 mg twice daily. Fasting plasma phospholipid concentrations of 12C- and 13C-labeled ALA, eicosapentaenoic acid (EPA; C20:5n-3), docosapentaenoic acid (DPA; C22:5n-3), and docosahexaenoic acid (DHA; C22:6n-3) were determined on days 19, 21, 23, 26, 27, and 28. To estimate hepatic conversion of n-3 fatty acids, a tracer model was developed based on the averaged 13C data of the participants. A similar tracee model was solved using the averaged 12C values, the kinetic parameters derived from the tracer model, and mean ALA consumption. ALA incorporation into plasma phospholipids was estimated by solving both models simultaneously. It was found that nearly 7% of dietary ALA was incorporated into plasma phospholipids. From this pool, 99.8% was converted into EPA and 1% was converted into DPA and subsequently into DHA. The limited incorporation of dietary ALA into the hepatic phospholipid pool contributes to the low hepatic conversion of ALA into EPA. A low conversion of ALA-derived EPA into DPA might be an additional obstacle for DHA synthesis. 10.1194/jlr.M400514-JLR200 KW - diet KW - health KW - omega3 AU - Goyens, Petra AU - Spilker, Mary AU - Zock, Peter AU - Katan, Martijn AU - Mensink, Ronald PY - 2005/07/01/ UR - http://dx.doi.org/10.1194/jlr.M400514 ER -