Impact of a Standard Rodent Chow Diet on Tissue n-6 Fatty Acids, [Delta]9-Desaturation Index, and Plasmalogen Mass in Rats Fed for One Year

• Published in: Lipids Vol. 50; no. 11; p. 1069
• Main Authors: Pédrono, F, Boulier-monthéan, N, Catheline, D, Legrand, P
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.11.2015
• Subjects: Erythrocytes; Fatty acids; Lipids; Rodents
• ISSN: 0024-4201; 1558-9307
• DOI: 10.1007/s11745-015-4068-y

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 [Delta]5- and [Delta]6-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 [Delta]9-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.