The effect of linoleic acid on the whole body synthesis rates of polyunsaturated fatty acids from α-linolenic acid and linoleic acid in free-living rats.

Autor: Domenichiello AF; Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 3E2, Canada., Kitson AP; Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 3E2, Canada., Chen CT; Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 3E2, Canada., Trépanier MO; Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 3E2, Canada., Stavro PM; Bunge Ltd. White Plains, NY, 10606, USA., Bazinet RP; Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 3E2, Canada. Electronic address: richard.bazinet@utoronto.ca.
Jazyk: angličtina
Zdroj: The Journal of nutritional biochemistry [J Nutr Biochem] 2016 Apr; Vol. 30, pp. 167-76. Date of Electronic Publication: 2015 Dec 12.
DOI: 10.1016/j.jnutbio.2015.11.016
Abstrakt: Docosahexaenoic acid (DHA) is thought to be important for brain function. The main dietary source of DHA is fish, however, DHA can also be synthesized from precursor omega-3 polyunsaturated fatty acids (n-3 PUFA), the most abundantly consumed being α-linolenic acid (ALA). The enzymes required to synthesize DHA from ALA are also used to synthesize longer chain omega-6 (n-6) PUFA from linoleic acid (LNA). The large increase in LNA consumption that has occurred over the last century has led to concern that LNA and other n-6 PUFA outcompete n-3 PUFA for enzymes involved in DHA synthesis, and therefore, decrease overall DHA synthesis. To assess this, rats were fed diets containing LNA at 53 (high LNA diet), 11 (medium LNA diet) or 1.5% (low LNA diet) of the fatty acids with ALA being constant across all diets (approximately 4% of the fatty acids). Rats were maintained on these diets from weaning for 8 weeks, at which point they were subjected to a steady-state infusion of labeled ALA and LNA to measure DHA and arachidonic acid (ARA) synthesis rates. DHA and ARA synthesis rates were generally highest in rats fed the medium and high LNA diets, while the plasma half-life of DHA was longer in rats fed the low LNA diet. Therefore, increasing dietary LNA, in rats, did not impair DHA synthesis; however, low dietary LNA led to a decrease in DHA synthesis with tissue concentrations of DHA possibly being maintained by a longer DHA half-life.
(Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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