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.

Sciadonic acid derived from pine nuts as a food component to reduce plasma triglycerides by inhibiting the rat hepatic Δ9-desaturase

“…The effect of diets was first analyzed on plasma. The lipid content of plasma from the control diet, including triglycerides and cholesterol, was coherent with a previous work performed on the same rat strain fed with standard rodent chow 25 (Fig. 2a).…”

Liver phospholipids fatty acids composition in response to different types of diets in rats of both sexes

“…The physiologic role of VA has yet to be elucidated. Recent studies have shown that VA could represent a potential marker of various diseases such as chronic kidney disease, hypertension or heart failure [24]. Ma et al [25] demonstrated that VA was positively correlated with lower diabetes risk.…”

The Hypotriglyceridemic Effect of Sciadonic Acid is Mediated by the Inhibition of Δ9‐Desaturase Expression and Activity

“…Lipids were saponified with 0.5 mol L –1 NaOH in methanol at 70 °C for 20 min and methylated with BF 3 (14% in methanol) at 70 °C for 15 min. FA methyl esters (FAME) were separated using a 7890N Agilent GC equipped with a BPX70 capillary column and coupled to a 5975C mass spectrometer (Agilent Technologies, Les Ulis, France) following procedures previously described . Agilent MSD ChemStation software was used for data acquisition.…”

“…FA methyl esters (FAME) were separated using a 7890N Agilent GC equipped with a BPX70 capillary column and coupled to a 5975C mass spectrometer (Agilent Technologies, Les Ulis, France) following procedures previously described. [16] Agilent MSD ChemStation software was used for data acquisition. Components were identified from the retention time of FAME standards and also by using the NIST mass spectral library (version 2.01).…”