As the largest secondary lymphoid organ, the spleen plays an important role in immune responses. The role of arachidonic acid (ARA) and its 20‐carbon eicosanoids in modulating immune function has long been of interest. However, recent advances have enabled the identification of numerous other n‐6 and n‐3 polyunsaturated fatty acid (PUFA)‐derived oxylipins. Here, we investigate the effects of diet and sex on the spleen nonesterified oxylipin profiles and phospholipid and neutral lipid PUFA composition in Sprague–Dawley rats supplemented with oils rich in α‐linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), or linoleic acid. Dietary ALA, EPA, and DHA resulted in lower levels of ARA and ARA oxylipins. Oxylipins derived from other n‐6 PUFA were also reduced despite no or opposite effect on their PUFA levels. Each diet also resulted in higher levels of oxylipins almost exclusively derived from the supplemented PUFA, despite PUFA in the same biosynthetic pathway also often being increased. Further, while oxylipin differences often reflected changes to phospholipid PUFA, there were instances where they corresponded more closely to changes in neutral lipid PUFA. With respect to sex effects, >50% of lipoxygenase ARA‐derived oxylipins were higher in males in at least one diet group, while multiple DHA oxylipins were lower in males only in rats provided the DHA diet. This fundamental description of oxylipin composition in the spleen, including the influence of diet and sex and the relationship to PUFA composition, will help inform future studies examining the functions of these oxylipins under physiological and pathological conditions.

中文翻译：

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饮食中多不饱和脂肪酸的来源和性别会改变脾脏中的脂磷脂和多不饱和脂肪酸的分布。

作为最大的次级淋巴器官，脾脏在免疫反应中起重要作用。花生四烯酸（ARA）及其20碳类二十烷酸在调节免疫功能中的作用早已引起人们的关注。但是，最近的进展使得能够鉴定出许多其他的n-6和n-3多不饱和脂肪酸（PUFA）衍生的脂素。在这里，我们研究饮食和性别对补充富含α-亚麻酸（ALA），二十碳五烯酸（EPA），二十二碳六烯酸的油的Sprague-Dawley大鼠的脾脏非酯化脂蛋白谱以及磷脂和中性脂质PUFA组成的影响。 DHA）或亚油酸。饮食中的ALA，EPA和DHA导致ARA和ARA脂质的含量降低。尽管对其他n-6 PUFA的羟脯氨酸的PUFA水平没有影响或相反，但它们的含量也降低了。尽管同一生物合成途径中的PUFA也经常增加，但每种饮食也导致几乎完全来自补充PUFA的较高水平的脂蛋白。此外，虽然脂蛋白的差异通常反映了磷脂PUFA的变化，但在某些情况下，它们更接近中性脂质PUFA的变化。就性别影响而言，至少一个饮食组中，雄性中大于50％的脂氧合酶ARA衍生的脂蛋白较高，而仅提供DHA饮食的大鼠中，雄性中的多种DHA脂蛋白较低。脾脏中脂蛋白组成的基本描述，包括饮食和性别的影响以及与PUFA组成的关系，将有助于将来在生理和病理条件下研究这些脂蛋白功能的研究。