This Article Full Text Full Text (PDF) Supplemental Data Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints, Permissions and Rights Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barrows, B. R. Articles by Parks, E. J. Search for Related Content PubMed PubMed Citation Articles by Barrows, B. R. Articles by Parks, E. J. Related Collections Lipid Metabolism

Contributions of Different Fatty Acid Sources to Very Low-Density Lipoprotein-Triacylglycerol in the Fasted and Fed States

Department of Food Science and Nutrition and Division of Endocrinology and Diabetes, University of Minnesota, St. Paul, Minnesota 55108

Address all correspondence and requests for reprints to: Elizabeth J. Parks, Ph.D., Center for Human Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9052. E-mail: Elizabeth.Parks{at}UTSoutwestern.edu.

Context: The liver’s regulation of fatty acids (FAs) postprandially may contribute to risk of metabolic diseases.

Objective: Measurements of steady-state metabolism were used to investigate sources of FAs used for very low-density lipoprotein (VLDL)-triacylglycerol (TG) synthesis during fasting and feeding in vivo.

Design/Intervention: Subjects were duodenally fed a formula labeled with the stable isotope glyceryl tri-palmitate-d₃₁ and iv infused with [1,2,3,4-¹³C₄]-palmitatic acid and [1-¹³C₁]-acetate to quantitate the liver’s use of FAs originating from adipose tissue and de novo lipogenesis.

Setting/Participants: This study of healthy men (n = 12; body mass index, 24.4 ± 2.7 kg/m²) was conducted at a General Clinical Research Center.

Main Outcome Measures: Concentrations of metabolites during fasting and feeding, sources of FAs used for lipoprotein synthesis, rate of appearance of serum nonesterified FA (NEFA), and VLDL-TG were measured.

Results: During fasting, 77.2 ± 14.0% of VLDL-TG was derived from adipose FA recycling and 4.0 ± 3.6% from lipogenesis; with feeding, 43.6 ± 18.6% came from adipose FAs (P < 0.001), 8.2 ± 5.1% from lipogenesis (P < 0.001), 15.2 ± 13.7% from uptake of chylomicron-remnant TG, and 10.3 ± 6.9% from dietary FA spillover into the serum NEFA pool. Fed-state VLDL-TG from NEFA reesterification decreased in proportion to the reduction in adipose NEFA appearance.

Conclusion: These data: 1) quantify the extent to which the healthy liver manages its use of different sources of FAs that flow to it, 2) demonstrate how the postprandial reduction in adipose-NEFA flux may be partially replaced by other sources, and 3) highlight the potential for dietary FA spillover to support the continued dominance of NEFA as a substrate for VLDL-TG synthesis.

This article has been cited by other articles:

				A. Grefhorst and E. J. Parks Reduced insulin-mediated inhibition of VLDL secretion upon pharmacological activation of the liver X receptor in mice J. Lipid Res., July 1, 2009; 50(7): 1374 - 1383. [Abstract] [Full Text] [PDF]

				A. Bergouignan, G. Trudel, C. Simon, A. Chopard, D. A. Schoeller, I. Momken, S. B. Votruba, M. Desage, G. C. Burdge, G. Gauquelin-Koch, et al. Physical Inactivity Differentially Alters Dietary Oleate and Palmitate Trafficking Diabetes, February 1, 2009; 58(2): 367 - 376. [Abstract] [Full Text] [PDF]

				S. Rigazio, H.-R. Lehto, H. Tuunanen, K. Nagren, M. Kankaanpaa, C. Simi, R. Borra, A. G. Naum, R. Parkkola, J. Knuuti, et al. The lowering of hepatic fatty acid uptake improves liver function and insulin sensitivity without affecting hepatic fat content in humans Am J Physiol Endocrinol Metab, August 1, 2008; 295(2): E413 - E419. [Abstract] [Full Text] [PDF]

				M. Adiels, S.-O. Olofsson, M.-R. Taskinen, and J. Boren Overproduction of Very Low-Density Lipoproteins Is the Hallmark of the Dyslipidemia in the Metabolic Syndrome Arterioscler Thromb Vasc Biol, July 1, 2008; 28(7): 1225 - 1236. [Abstract] [Full Text] [PDF]

				E. J. Parks, L. E. Skokan, M. T. Timlin, and C. S. Dingfelder Dietary Sugars Stimulate Fatty Acid Synthesis in Adults J. Nutr., June 1, 2008; 138(6): 1039 - 1046. [Abstract] [Full Text] [PDF]

				H. Duez, B. Lamarche, R. Valero, M. Pavlic, S. Proctor, C. Xiao, L. Szeto, B. W. Patterson, and G. F. Lewis Both Intestinal and Hepatic Lipoprotein Production Are Stimulated by an Acute Elevation of Plasma Free Fatty Acids in Humans Circulation, May 6, 2008; 117(18): 2369 - 2376. [Abstract] [Full Text] [PDF]

				M. F-F Chong, L. Hodson, A. S Bickerton, R. Roberts, M. Neville, F. Karpe, K. N Frayn, and B. A Fielding Parallel activation of de novo lipogenesis and stearoyl-CoA desaturase activity after 3 d of high-carbohydrate feeding Am. J. Clinical Nutrition, April 1, 2008; 87(4): 817 - 823. [Abstract] [Full Text] [PDF]

				L. Hodson, A. S.T. Bickerton, S. E. McQuaid, R. Roberts, F. Karpe, K. N. Frayn, and B. A. Fielding The Contribution of Splanchnic Fat to VLDL Triglyceride Is Greater in Insulin-Resistant Than Insulin-Sensitive Men and Women: Studies in the Postprandial State Diabetes, October 1, 2007; 56(10): 2433 - 2441. [Abstract] [Full Text] [PDF]

				L. M Mangravite, K. Dawson, R. R Davis, J. P Gregg, and R. M Krauss Fatty acid desaturase regulation in adipose tissue by dietary composition is independent of weight loss and is correlated with the plasma triacylglycerol response Am. J. Clinical Nutrition, September 1, 2007; 86(3): 759 - 767. [Abstract] [Full Text] [PDF]

				F. Magkos, B. W. Patterson, and B. Mittendorfer Reproducibility of stable isotope-labeled tracer measures of VLDL-triglyceride and VLDL-apolipoprotein B-100 kinetics J. Lipid Res., May 1, 2007; 48(5): 1204 - 1211. [Abstract] [Full Text] [PDF]

				R. B. Heath, F. Karpe, R. W. Milne, G. C. Burdge, S. A. Wootton, and K. N. Frayn Dietary fatty acids make a rapid and substantial contribution to VLDL-triacylglycerol in the fed state Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E732 - E739. [Abstract] [Full Text] [PDF]

				A. S.T. Bickerton, R. Roberts, B. A. Fielding, L. Hodson, E. E. Blaak, A. J.M. Wagenmakers, M. Gilbert, F. Karpe, and K. N. Frayn Preferential Uptake of Dietary Fatty Acids in Adipose Tissue and Muscle in the Postprandial Period Diabetes, January 1, 2007; 56(1): 168 - 176. [Abstract] [Full Text] [PDF]

				F. Magkos, B. W. Patterson, and B. Mittendorfer No effect of menstrual cycle phase on basal very-low-density lipoprotein triglyceride and apolipoprotein B-100 kinetics Am J Physiol Endocrinol Metab, December 1, 2006; 291(6): E1243 - E1249. [Abstract] [Full Text] [PDF]

				E. J. Parks and M. K. Hellerstein Thematic review series: Patient-Oriented Research. Recent advances in liver triacylglycerol and fatty acid metabolism using stable isotope labeling techniques J. Lipid Res., August 1, 2006; 47(8): 1651 - 1660. [Abstract] [Full Text] [PDF]