The incorporation of linolenic acid and docosahexaenoic acid into liver and brain lipids of developing rats

Sinclair, Andrew J.; Crawford, M. A.

doi:10.1016/0014-5793(72)80557-x

Cited by 76 publications

(34 citation statements)

References 8 publications

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“…The lower levels of DHA found in RBC PE ofthese infants compared with those previously reported in cord blood (16) and after human milk feeding (15,16) suggest that VLBW infants do not generate DHA from LLA at optimal rates. Preformed 20-and 22-carbon fatty acids accumulate in membranes more avidly than their 18-carbon precursors (29). During marine oil supplementation, RBC PE DHA plateaued in these infants at 7.0 to 8.0% of total fatty acids; i.e.…”

Section: Acute Effects Of Marine Oil Supplementation On Dha Epa Andmentioning

confidence: 87%

Long-Term Feeding of Formulas High in Linolenic Acid and Marine Oil to Very Low Birth Weight Infants: Phospholipid Fatty Acids

et al. 1991

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Section: Acute Effects Of Marine Oil Supplementation On Dha Epa Andmentioning

confidence: 87%

Long-Term Feeding of Formulas High in Linolenic Acid and Marine Oil to Very Low Birth Weight Infants: Phospholipid Fatty Acids

et al. 1991

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“…The latter are more rapidly incorporated into plasma and membrane lipids and produce more rapid effects, compared with LnA (Sinclair & Crawford, 1972;Sinclair, 1975;FAO/WHO, 1978;Dyerberg et al 1980, Sanders & Younger, 1981Sanders & Roshanai, 1983). Relatively large reserves of LA in body fat, as are found in vegans, would tend to slow down the formation of long-chain "-3 FA from LnA (Sanders & Naismith, 1980).…”

Section: Effects Of Dietary Lna V Long-chain N-3 Derivativesmentioning

confidence: 99%

α-Linolenic acid as a regulator of the metabolism of arachidonic acid: dietary implications of the ratio, n-6:n-3 fatty acids

Budowski¹,

Crawford²

1985

Proc. Nutr. Soc.

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Abstract We quantified the rates of incorporation of alinolenic acid (a-LNA; 18:3n-3) into ''stable'' lipids (triacylglycerol, phospholipid, cholesteryl ester) and the rate of conversion of a-LNA to docosahexaenoic acid (DHA; 22: 6n-3) in the liver of awake male rats on a high-DHA-containing diet after a 5-min intravenous infusion of [1][2][3][4][5][6][7][8][9][10][11][12][13][14] C]a-LNA. At 5 min, 72.7% of liver radioactivity (excluding unesterified fatty acid radioactivity) was in stable lipids, with the remainder in the aqueous compartment.

…”

mentioning

confidence: 99%

Low liver conversion rate of α-linolenic to docosahexaenoic acid in awake rats on a high-docosahexaenoate-containing diet

Igarashi

Chang

et al. 2006

Journal of Lipid Research

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We quantified the rates of incorporation of alinolenic acid (a-LNA; 18:3n-3) into ''stable'' lipids (triacylglycerol, phospholipid, cholesteryl ester) and the rate of conversion of a-LNA to docosahexaenoic acid (DHA; 22: 6n-3) in the liver of awake male rats on a high-DHA-containing diet after a 5-min intravenous infusion of [1][2][3][4][5][6][7][8][9][10][11][12][13][14] C]a-LNA. At 5 min, 72.7% of liver radioactivity (excluding unesterified fatty acid radioactivity) was in stable lipids, with the remainder in the aqueous compartment. Using our measured specific activity of liver a-LNA-CoA, in the form of the dilution coefficient l a-LNA-CoA , we calculated incorporation rates of unesterified a-LNA into liver triacylglycerol, phospholipid, and cholesteryl ester as 2,401, 749, and 9.6 nmol/s/g 3 10 24, respectively, corresponding to turnover rates of 3.2, 8.7, and 2.9%/min and half-lives of 8-24 min. A lower limit for the DHA synthesis rate from a-LNA equaled 15.8 nmol/s/g 3 10 24 (0.5% of the net incorporation rate). Thus, in rats on a high-DHA-containing diet, rates of b-oxidation and esterification of a-LNA into stable liver lipids are high, whereas its conversion to DHA is comparatively low and insufficient to supply significant DHA to the brain. High incorporation and turnover rates likely reflect a high secretion rate by liver of stable lipids within very low density lipoproteins. -Igarashi, M., K. Ma, L. Chang, J. M. Bell, S. I. Rapoport, and J. C. DeMar, Jr. Low liver conversion rate of a-linolenic to docosahexaenoic acid in awake rats on a high-docosahexaenoate-containing diet. J. Lipid Res. 2006Res. . 47: 1812Res. -1822 Supplementary key words incorporation . turnover . synthesis . pulse labeling . infusion . diet Docosahexaenoic acid (DHA; 22:6n-3) is a nutritionally essential PUFA that must be obtained directly through the diet or be synthesized from its dietary essential precursor, a-linolenic acid (a-LNA; 18:3n-3). Mammalian tissues can convert a-LNA to DHA through serial steps of desaturation and elongation with final peroxisomal chain shortening (1-3). Both D5 and D6 desaturases participate in this conversion, but the D6 desaturase is considered to be rate-limiting (1, 4). Human and rat D5 and D6 desaturases are expressed abundantly in brain, liver, and heart (5, 6).Controversy remains regarding the extent of DHA synthesis in brain from a-LNA, compared with its delivery by blood to brain as DHA synthesized from a-LNA in the liver. In immature rats, Scott and Bazan (7) concluded that the brain does not synthesize its own DHA to a significant extent but that DHA converted from a-LNA in the liver can contribute to brain DHA via the blood stream. In adult rats fed a high-DHA-containing diet [2.3% (w/w) of total fatty acid], we recently used an in vivo kinetic pulselabeling model that confirmed a low synthesis rate of DHA from a-LNA in brain (2), as proposed for immature rats (see above), and also showed that a-LNA was largely b-oxidized or esterified unchanged into brain phospholipid. We d...

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The incorporation of linolenic acid and docosahexaenoic acid into liver and brain lipids of developing rats

Cited by 76 publications

References 8 publications

Long-Term Feeding of Formulas High in Linolenic Acid and Marine Oil to Very Low Birth Weight Infants: Phospholipid Fatty Acids

Long-Term Feeding of Formulas High in Linolenic Acid and Marine Oil to Very Low Birth Weight Infants: Phospholipid Fatty Acids

α-Linolenic acid as a regulator of the metabolism of arachidonic acid: dietary implications of the ratio, n-6:n-3 fatty acids

Low liver conversion rate of α-linolenic to docosahexaenoic acid in awake rats on a high-docosahexaenoate-containing diet

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