Significant utilization of dietary arachidonic acid is for brain adrenic acid in baboon neonates.
Dietary arachidonic acid (20:4n-6) utilization in-vivo for carbon recycling into de-novo lipogenesis and conversion to n-6 long chain polyunsaturates was investigated in baboon neonates using [U-(13)C]20:4n-6. Neonates consuming a formula typical of human milk received a single oral dose of [(13)C]arachidonic acid in sn-2 position of either triglyceride or phosphatidylcholine at 18-19 days of postnatal life. Neonate brain, retina, liver, and plasma were obtained 10 days later (28-29 days of life). Low isotopic enrichment (0.27-1.0%Total label) was detected in dihomo-gamma-linolenic acid (20:3n-6) in all tissues, but label incorporation into saturates or monounsaturates was not detected. In neonate brain and retina, 16% and 11% of total label was recovered in 22:4n-6, respectively. The relative contribution of dietary fatty acids to postnatal brain 22:4n-6 accretion can be estimated for dietary 20:4n-6 and preformed 22:4n-6 as 17% and 8%, respectively, corresponding to efficiencies of 0.48% and 0.54% of dietary levels, respectively. These results demonstrate in term baboon neonates that in vivo 1) 20:4n-6 was retroconverted to 20:3n-6, 2) 20:4n-6 did not contribute significantly to de novo lipogenesis of saturates and monounsaturates, and 3) the preformed 20:4n-6 contribution to brain 22:4n-6 accumulation was quantitatively a significant metabolic fate for dietary 20:4n-6.
Wijendran
Vasuki
V
Division of Nutritional Sciences, Savage Hall, Cornell University, Ithaca, NY 14853, USA.
Lawrence
Peter
P
Diau
Guan-Yeu
GY
Boehm
G
G
Nathanielsz
P W
PW
Brenna
J T
JT
D000818:Animals; D000831:Animals, Newborn; D016718:Arachidonic Acid / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002247:Carbon Isotopes; D004042:Dietary Fats, Unsaturated / Q000378:metabolism*; D004883:Erucic Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated; D005260:Female; D005865:Gestational Age; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D008895:Milk, Human; D010215:Papio; D011247:Pregnancy
D002247:Carbon Isotopes; D004042:Dietary Fats, Unsaturated; D004883:Erucic Acids; D005231:Fatty Acids, Unsaturated; C011395:adrenic acid; D016718:Arachidonic Acid