Original Article

Linoleic acid kinetics and conversion to arachidonic acid in the pregnant and fetal baboon

Correspondence to: J. Thomas Brenna

Linoleic acid plasma kinetics in pregnant baboons and its conversion to long chain polyunsaturates (LCP) in fetal organs is characterized over a 29-day period using stable isotope tracers. Pregnant baboons consumed an LCP-free diet and received [U-¹³C]linoleic acid (18:2*) in their third trimester of gestation. In maternal plasma, 18:2* dropped to near baseline by 14 days post-dose, while labeled arachidonic acid (20:4*) plateaued at 10 days at about 70% of total labeled fatty acids. After 2;–5 days, total tracer fatty acids decreased in visceral organs, but increased in the fetal brain. Maximal fetal incorporation of 18:2* was 1;–2 days post-dose; thereafter it dropped while 20:4* increased reciprocally. Labeled 20:4 replaced 18:2* in neural tissues by 5 days post-dose. In liver, kidney, and lung, 20:4* became dominant by 12 days, but in heart the crossover was >29 days. Fetal brain 20:4* plateaued by 21 days at 0.025% of dose, while fetal liver 20:4* was constant from 1 to 29 days at 0.006% of dose.

Under these dietary conditions we estimate that the fetus derives about 50% its 20:4 requirement from conversion of dietary 18:2, with the balance from maternal stores, and conclude that 1) fetal organs accumulate 18:2 within a day of a maternal dose and convert much of it to 20:4 within weeks, 2) modest dietary 18:2 levels may support fetal brain requirements for 20:4, and 3) the brain retains n;–6 fatty acids uniquely compared with major visceral organs.—Su, H-M., T. N. Corso, P. W. Nathanielsz, and J. T. Brenna. Linoleic acid kinetics and converstion to arachidonic acid in the pregnant and fetal baboon. J. Lipid Res. 40: 1304;–1311.

Supplementary key words: linoleic acid, arachidonic acid, brain, retina, development

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

This article has been cited by other articles:

				Y. H. Lin and N. Salem Jr. Whole body distribution of deuterated linoleic and {alpha}-linolenic acids and their metabolites in the rat J. Lipid Res., December 1, 2007; 48(12): 2709 - 2724. [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]

				V. Wijendran, P. Lawrence, G.-Y. Diau, G. Boehm, P. W. Nathanielsz, and J. T. Brenna Significant utilization of dietary arachidonic acid is for brain adrenic acid in baboon neonates J. Lipid Res., May 1, 2002; 43(5): 762 - 767. [Abstract] [Full Text] [PDF]