Fatty acid desaturase indices in rats: Associations between plasma, liver and adipose tissue lipid fractions and the effects of a high-fat diet and diet-induced obesity
(English)Manuscript (preprint) (Other academic)
Background: Alterations in fatty acid (FA) desaturase indices are linked to obesity-related disorders. As desaturases affect FA composition increased understanding of their regulation across lipid fractions with varying functions is essential. In this study we have examined desaturases and selected FAs to establish their degree of co-regulation in five different lipid fractions and under different dietary conditions, including diet-induced obesity (DIO).
Methods: Sprague-Dawley rats were randomly grouped into three groups, one fed a chow diet ad libitum (control) and two fed a high-fat diet (HFD): one ad libitum (AL-HFD) and the other one calorically pair fed to the chow-fed group (HFD-paired). FA composition in subcutaneous adipose tissue triacylglycerols (SAT-TG), liver (phospholipids and triacylglycerols) and plasma (phospholipids and cholesterol esters) was assessed. Delta-5 desaturase (D5D), delta-6 desaturase (D6D) and stearoyl-CoA-desaturase 1 (SCD-16) indices were calculated from product-to-precursor FA ratios and proportions of long-chain FAs were measured.
Results: Positive correlations were found for the desaturase indices between the five lipid fractions, especially for SCD-16 and almost exclusively between liver and plasma fractions. Only SCD-16 in SAT-TG of the AL-HFD group correlated with gain in body weight. Independent of weight gain, the HFD decreased all SCD-16 indices and most FA proportions, but D5D and D6D indices were fraction- and tissue-dependently increased.
Conclusion: Desaturase indices are especially correlated for SCD-16 and between lipid and plasma lipid fractions, suggesting that SAT-TG desaturation is differentially regulated compared with the other studied lipid fractions. The correlations are however influenced by diet and weight gain, further suggesting such factors should be taken into account when using desaturase indices.
diet-induced obesity, delta-5, delta-6, scd-1, fatty acid composition, high-fat diet, subcutaneous adipose tissue, scd-16
Nutrition and Dietetics
Research subject Nutrition; Nutrition
IdentifiersURN: urn:nbn:se:uu:diva-196190OAI: oai:DiVA.org:uu-196190DiVA: diva2:609429