title: Comparative effects of well-balanced diets enriched in α-linolenic or linoleic acids on LC-PUFA metabolism in rat tissues.
abstract: The intake of the essential fatty acid precursor α-linolenic acid (ALA) contributes to ensure adequate n-3 long-chain polyunsaturated fatty acid (LC-PUFA) bioavailability. Conversely, linoleic acid (LA) intake may compromise tissue n-3 PUFA status as its conversion to n-6 LC-PUFA shares a common enzymatic pathway with the n-3 family. This study aimed to measure dietary ALA and LA contribution to LC-PUFA biosynthesis and tissue composition. Rats were fed with control or experimental diets moderately enriched in ALA or LA for 8 weeks. Liver Δ6- and Δ5-desaturases were analyzed and FA composition was determined in tissues (red blood cells, liver, brain and heart). Hepatic Δ6-desaturase activity was activated with both diets, and Δ5-desaturase activity only with the ALA diet. The ALA diet led to higher n-3 LC-PUFA composition, including DHA in brain and heart. The LA diet reduced n-3 content in blood, liver and heart, without impacting n-6 LC-PUFA composition. At levels relevant with human nutrition, increasing dietary ALA and reducing LA intake were both beneficial in increasing n-3 LC-PUFA bioavailability in tissues.
authors.affiliation: Laboratoire de Biochimie et Nutrition Humaine, INRA USC 2012, Agrocampus Ouest, Rennes, France.
authors.forename: H
authors.initials: H
authors.lastname: Blanchard
authors.forename: F
authors.initials: F
authors.lastname: Pédrono
authors.forename: N
authors.initials: N
authors.lastname: Boulier-Monthéan
authors.forename: D
authors.initials: D
authors.lastname: Catheline
authors.forename: V
authors.initials: V
authors.lastname: Rioux
authors.forename: P
authors.initials: P
authors.lastname: Legrand
mesh_terms: D000818:Animals; D000090943:Delta-5 Fatty Acid Desaturase; D004032:Diet; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006321:Heart; D008041:Linoleic Acids / Q000008:administration & dosage*; D009928:Organ Specificity; D051381:Rats; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000008:administration & dosage*
chemical_list: D000090943:Delta-5 Fatty Acid Desaturase; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D017962:alpha-Linolenic Acid; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C474452:delta 6-desaturase, rat