HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Su, H.-M. Articles by Brenna, J. T. Search for Related Content PubMed PubMed Citation Articles by Su, H.-M. Articles by Brenna, J. T. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 42, 581-586, April 2001
Copyright © 2001 by Lipid Research, Inc.

Original Article

Fetal baboons convert 18:3n-3 to 22:6n-3 in vivo: a stable isotope tracer study

Correspondence to: J. Thomas Brenna, To whom correspondence should be addressed., jtb4{at}cornell.edu (E-mail)

Using [¹³C]-tracers and direct fetal doses, we show for the first time that the fetal primate converts -linolenic acid (18:3) to docosahexaenoic acid (22:6) in vivo, and we estimate the relative bioefficacy of the two substrates for brain 22:6 accretion. Pregnant female baboons consumed a diet free of long chain polyunsaturates (LCP), with n-6/n-3 ratio of 10/1. In the third trimester of pregnancy (normal gestation = 182 days), they were instrumented with chronic indwelling catheters in the maternal femoral artery and the fetal jugular artery. Doses of either [U-¹³C]-18:3 (18:3*, n = 3) or [U-¹³C]-22:6 (22:6*, n = 2) were administered directly to the fetus. Blood was collected from fetus and mother, and the fetus was taken by cesarean section when electromyographic activity indicated that parturition was imminent. Fetal liver, brain, retina, and retinal pigment epithelium (RPE) were collected, and ¹³C fatty acids determined. In 18:3*- dosed animals, labeled n-3 LCP were detected in fetal plasma at 1 day post-dose and peaked at 2;–3 days; brain 22:6* was constant at 3, 5, and 9 days post-dose, at 0.57 ± 0.03 percent of dose (%Dose). In 22:6*- dosed animals, brain 22:6* was similar at 3 and 9 days post-dose (4.64 ± 0.43%Dose). From these data, we estimate that preformed 22:6 in the fetal bloodstream is 8-fold more efficacious for brain 22:6 accretion than is 18:3. Retina 22:6* was stable at about 0.0008%Dose from 3 to 9 days in 18:3-dosed animals, but RPE 22:6* dropped over the period; brain results were consistent with these observations. Liver showed about 0.5%Dose in 22:6* and in intermediary n-3 fatty acid metabolites 20:5* and 22:5* at 3 days post-dose, and declined afterward. Back-transfer of labeled fatty acids to the maternal bloodstream was measurable but not sufficient to compromise the quantitative conversion data in fetuses.

We conclude 1) primate fetuses have the capacity to convert 18:3 to 22:6 in vivo; 2) fetal brain 22:6* as %Dose plateaus by 3 days post-dose; 3) fetal plasma 22:6 is about 8-fold more effective as a substrate for brain 22:6 accretion compared with 18:3; and 4) the fetal liver is likely to be an important site of 18:3 to 22:6 conversion.—Su, H-M., M-C. Huang, N. M. R. Saad, P. W. Nathanielsz, and J. T. Brenna. Fetal baboons convert 18:n-3 to 22:6n-3 in vivo: a stable isotope tracer study. J. Lipid Res. 2000. 42: 581;–586.

Supplementary key words: primates, perinatal, lipid nutrition, polyunsaturated fatty acids, docosahexaenoic acid, linolenic acid, in vivo desaturation, stable isotopes, isotope ratio mass spectrometry, long chain polyunsaturated fatty acid metabolism

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. Barcelo-Coblijn, E. J Murphy, R. Othman, M. H Moghadasian, T. Kashour, and J. K Friel Flaxseed oil and fish-oil capsule consumption alters human red blood cell n-3 fatty acid composition: a multiple-dosing trial comparing 2 sources of n-3 fatty acid Am. J. Clinical Nutrition, September 1, 2008; 88(3): 801 - 809. [Abstract] [Full Text] [PDF]

				M.-C. Huang, J. T. Brenna, A. C. Chao, C. Tschanz, D. A. Diersen-Schade, and H.-C. Hung Differential Tissue Dose Responses of (n-3) and (n-6) PUFA in Neonatal Piglets Fed Docosahexaenoate and Arachidonoate J. Nutr., September 1, 2007; 137(9): 2049 - 2055. [Abstract] [Full Text] [PDF]

				M. Igarashi, J. C. DeMar Jr., K. Ma, L. Chang, J. M. Bell, and S. I. Rapoport Upregulated liver conversion of {alpha}-linolenic acid to docosahexaenoic acid in rats on a 15 week n-3 PUFA-deficient diet J. Lipid Res., January 1, 2007; 48(1): 152 - 164. [Abstract] [Full Text] [PDF]

				K. M. Heinemann, M. K. Waldron, K. E. Bigley, G. E. Lees, and J. E. Bauer Long-Chain (n-3) Polyunsaturated Fatty Acids Are More Efficient than {alpha}-Linolenic Acid in Improving Electroretinogram Responses of Puppies Exposed during Gestation, Lactation, and Weaning J. Nutr., August 1, 2005; 135(8): 1960 - 1966. [Abstract] [Full Text] [PDF]

				P. L. L. Goyens, M. E. Spilker, P. L. Zock, M. B. Katan, and R. P. Mensink Compartmental modeling to quantify {alpha}-linolenic acid conversion after longer term intake of multiple tracer boluses J. Lipid Res., July 1, 2005; 46(7): 1474 - 1483. [Abstract] [Full Text] [PDF]

				C. J McNeil, A. M Finch, K. R Page, S. D Clarke, C. J Ashworth, and H. J McArdle The effect of fetal pig size and stage of gestation on tissue fatty acid metabolism and profile Reproduction, June 1, 2005; 129(6): 757 - 763. [Abstract] [Full Text] [PDF]

				J. Denomme, K. D. Stark, and B. J. Holub Directly Quantitated Dietary (n-3) Fatty Acid Intakes of Pregnant Canadian Women Are Lower than Current Dietary Recommendations J. Nutr., February 1, 2005; 135(2): 206 - 211. [Abstract] [Full Text] [PDF]

				E. Sarkadi-Nagy, V. Wijendran, G. Y. Diau, A. C. Chao, A. T. Hsieh, A. Turpeinen, P. Lawrence, P. W. Nathanielsz, and J. T. Brenna Formula feeding potentiates docosahexaenoic and arachidonic acid biosynthesis in term and preterm baboon neonates J. Lipid Res., January 1, 2004; 45(1): 71 - 80. [Abstract] [Full Text] [PDF]

				G.-Y. Diau, E. R. Loew, V. Wijendran, E. Sarkadi-Nagy, P. W. Nathanielsz, and J. T. Brenna Docosahexaenoic and Arachidonic Acid Influence on Preterm Baboon Retinal Composition and Function Invest. Ophthalmol. Vis. Sci., October 1, 2003; 44(10): 4559 - 4566. [Abstract] [Full Text] [PDF]

				D. E. Williard, S. D. Harmon, T. L. Kaduce, M. Preuss, S. A. Moore, M. E. C. Robbins, and A. A. Spector Docosahexaenoic acid synthesis from n-3 polyunsaturated fatty acids in differentiated rat brain astrocytes J. Lipid Res., September 1, 2001; 42(9): 1368 - 1376. [Abstract] [Full Text] [PDF]