Dietary LA and sex effects on oxylipin profiles in rat kidney, liver, and serum differ from their effects on PUFAs

Shan Leng,Tanja Winter,Harold M Aukema

doi:10.1194/jlr.m078097

Abstract

A vast literature on fatty acids in mammals exists, but comparable compositional data on oxylipins is lacking. Weanling Sprague-Dawley rats were therefore provided control diets or diets with higher linoleic acid (LA) or with higher LA and α-linolenic acid (LA+ALA) for 6 weeks. Kidneys, livers, and serum were analyzed for oxylipins and fatty acids. The proportion of tissue oxylipins derived from LA was greater than the relative proportion of LA itself, whereas arachidonic acid (AA) oxylipins were overrepresented in serum. Higher dietary LA increased kidney LA and AA oxylipins, despite not altering LA or AA. In liver, both LA and AA and their oxylipins were higher, whereas in serum only LA oxylipins were higher with higher dietary LA. Higher LA resulted in a higher ratio of n-6/n-3 PUFA-derived oxylipins; adding ALA to the LA diet mitigated this and many, but not all, effects of the LA diet. Approximately 40% of oxylipins detected were influenced by sex and, unlike their PUFA precursors, most (>90%) of these were higher in males. These differences in dietary LA and sex on oxylipin and fatty acid profiles further our understanding of the effects of fatty acids and may have implications for dietary LA recommendations.

Highlights

A vast literature on fatty acids in mammals exists, but comparable compositional data on oxylipins is lacking
In comparison to the mass amount of linoleic acid (LA), the oxylipins in kidney and liver derived from LA were proportionately higher than LA itself, and the opposite was true for arachidonic acid (AA) and the other n-6 oxylipins
The oxylipin profiles of rat kidney, liver, and serum presented provide fundamental data on these bioactive lipids. These compositional data complement the vast fatty acid literature that currently exists and provides an expanded perspective of the physiological effects of lipids based on fatty acid profiles

Summary

Introduction

A vast literature on fatty acids in mammals exists, but comparable compositional data on oxylipins is lacking. 40% of oxylipins detected were influenced by sex and, unlike their PUFA precursors, most (>90%) of these were higher in males These differences in dietary LA and sex on oxylipin and fatty acid profiles further our understanding of the effects of fatty acids and may have implications for dietary LA recommendations.—Leng, S., T. Dietary LA and sex effects on oxylipin profiles in rat kidney, liver, and serum differ from their effects on PUFAs. J. There is a vast and growing literature on fatty acids in mammals, but basic compositional data on the bioactive lipids derived from these fatty acids is currently lacking. One important set of bioactive lipids that mediate many of the effects of PUFAs are known as oxylipins. Because fatty acid composition is often interpreted under the assumption that many of its effects are mediated via the oxylipins that it produces, it is imperative to determine the actual oxylipin profile and how it is associated with the PUFA profile under normal conditions

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