title: Impact of a Standard Rodent Chow Diet on Tissue n-6 Fatty Acids, Δ9-Desaturation Index, and Plasmalogen Mass in Rats Fed for One Year.
abstract: Although many studies focus on senescence mechanisms, few habitually consider age as a biological parameter. Considering the effect of interactions between food and age on metabolism, here we depict the lipid framework of 12 tissues isolated from Sprague-Dawley rats fed standard rodent chow over 1 year, an age below which animals are commonly studied. The aim is to define relevant markers of lipid metabolism influenced by age in performing a fatty acid (FA) and dimethylacetal profile from total lipids. First, our results confirm impregnation of adipose and muscular tissues with medium-chain FA derived from maternal milk during early infancy. Secondly, when animals were switched to standard croquettes, tissues were remarkably enriched in n-6 FA and especially 18:2n-6. This impregnation over time was coupled with a decrease of the desaturation index and correlated with lower activities of hepatic Δ5- and Δ6-desaturases. In parallel, we emphasize the singular status of testis, where 22:5n-6, 24:4n-6, and 24:5n-6 were exceptionally accumulated with growth. Thirdly, 18:1n-7, usually found as a discrete FA, greatly accrued over the course of time, mostly in liver and coupled with Δ9-desaturase expression. Fourthly, skeletal muscle was characterized by a surprising enrichment of 22:6n-3 in adults, which tended to decline in older rats. Finally, plasmalogen-derived dimethylacetals were specifically abundant in brain, erythrocytes, lung, and heart. Most notably, a shift in the fatty aldehyde moiety was observed, especially in brain and erythrocytes, implying that red blood cell analysis could be a good indicator of brain plasmalogens.
authors.affiliation: Laboratoire de Biochimie et Nutrition Humaine, USC INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France. frederique.pedrono@agrocampus-ouest.fr.
authors.forename: F
authors.initials: F
authors.lastname: Pédrono
authors.affiliation: Laboratoire de Biochimie et Nutrition Humaine, USC INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France. nathalie.monthean@agrocampus-ouest.fr.
authors.forename: N
authors.initials: N
authors.lastname: Boulier-Monthéan
authors.affiliation: Laboratoire de Biochimie et Nutrition Humaine, USC INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France. daniel.catheline@agrocampus-ouest.fr.
authors.forename: D
authors.initials: D
authors.lastname: Catheline
authors.affiliation: Laboratoire de Biochimie et Nutrition Humaine, USC INRA 1378, Agrocampus Ouest, 65 rue de Saint Brieuc, 35042, Rennes cedex, France. philippe.legrand@agrocampus-ouest.fr.
authors.forename: P
authors.initials: P
authors.lastname: Legrand
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism; D004032:Diet; D004912:Erythrocytes / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D050602:Linoleoyl-CoA Desaturase / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D009765:Obesity / Q000378:metabolism* / Q000473:pathology; D010955:Plasmalogens / Q000378:metabolism*; D051381:Rats; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism
chemical_list: D000447:Aldehydes; D005227:Fatty Acids; D043371:Fatty Acids, Omega-6; D010955:Plasmalogens; C001634:fatty aldehyde; D013230:Stearoyl-CoA Desaturase; D050602:Linoleoyl-CoA Desaturase
keywords: 18:1n-7 (cis-vaccenic acid); 18:2n-6 (linoleic acid); Age; Desaturase; Liver; Medium-chain fatty acid; Plasmalogen; Rat; Skeletal muscle; Testis