Threshold changes in rat brain docosahexaenoic acid incorporation and concentration following graded reductions in dietary alpha-linolenic acid. (February 2016)

• Record Type: Journal Article
• Authors: Taha, Ameer Y.; Chang, Lisa; Chen, Mei
• Is Part Of: Prostaglandins, leukotrienes, and essential fatty acids. Volume 105(2016:Feb.)
• Page Start: 26
• Page End: 34
• Publication Date: 2016-02
• Subjects: α-LNA alpha-linolenic acid -- ANOVA analysis of variance -- AA arachidonic acid -- cPLA2 Ca2+-dependent cytosolic phospholipase A2 -- iPLA2 Ca2+-independent phospholipase A2 -- CE cholesteryl ester -- ChoGpl choline glycerophospholipid -- COX cyclooxygenase -- DHA docosahexaenoic acid -- EtnGpl ethanolamine glycerophospholipid -- FAMEs fatty acid methyl esters -- GC gas-chromatography -- LA linoleic acid -- LOX lipoxygenase -- PtdIns phosphatidylinositol -- PET positron emitting tomography -- PtdSer phosphatidylserine -- PUFA polyunsaturated fatty acids -- TLs total lipids -- TLC thin layer chromatography -- TG triacylglyceride; Graded reduction -- Polyunsaturated fatty acids (PUFAs) -- Docosahexaenoic acid (DHA) -- Alpha-linolenic acid -- Threshold -- Brain DHA metabolism; Lipids -- Periodicals; Unsaturated fatty acids -- Periodicals; Prostaglandins -- Periodicals; Leukotrienes -- Periodicals; Fatty Acids, Unsaturated -- Periodicals; Acides gras insaturés -- Périodiques; Prostaglandines -- Périodiques; Leucotriènes -- Périodiques; Lipides -- Périodiques; 612.01577
• DOI: 10.1016/j.plefa.2015.12.002
• Languages: English
• ISSNs: 0952-3278

Abstract

Abstract: Background: This study tested the dietary level of alpha-linolenic acid (α-LNA, 18:3n-3) required to maintain brain 14 C-Docosahexaenoic acid (DHA, 22:6n-3) metabolism and concentration following graded α-LNA reduction. Methods: Fischer-344 (CDF) male rat pups (18–21 days old) were randomized to the AIN-93G diet containing as a % of total fatty acids, 4.6% ("n-3 adequate"), 3.6%, 2.7%, 0.9% or 0.2% ("n-3 deficient") α-LNA for 15 weeks. Rats were intravenously infused with 14 C-DHA to steady state for 5 min, serial blood samples collected to obtain plasma, and brains excised following microwave fixation. Labeled and unlabeled DHA concentrations were measured in plasma and brain to calculate the incorporation coefficient, k*, and incorporation rate, J in . Results: Compared to 4.6% α-LNA controls, k * was significantly increased in ethanolamine glycerophospholipids in the 0.2% α-LNA group. Circulating unesterified DHA and brain incorporation rates ( J in ) were significantly reduced at 0.2% α-LNA. Brain total lipid and phospholipid DHA concentrations were reduced at or below 0.9% α-LNA. Conclusion: Threshold changes for brain DHA metabolism and concentration were maintained at or below 0.9% dietary α-LNA, suggesting the presence of homeostatic mechanisms to maintain brain DHA metabolism when dietary α-LNA intake is low.