Palombo J D, DeMichele S J, Lydon E, Bistrian B R
Department of Surgery, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, Massachusetts, USA.
JPEN J Parenter Enteral Nutr. 1997 May-Jun;21(3):123-32. doi: 10.1177/0148607197021003123.
Arachidonic acid (AA) present in lung and liver immune cell phospholipids is the precursor of eicosanoids that promote neutrophil margination, leading to tissue injury and inflammation. Administration of novel enteral formulations low in linoleic acid (LA) and containing eicosapentaenoic acid (EPA) from fish oil and gamma-linolenic acid (GLA) from borage oil displaces AA and promotes cell formation of eicosanoids with reduced inflammatory potential. The present study was undertaken to determine whether or not short-term provision of enteral diets containing GLA, EPA, or both in a cyclic fashion modulated the fatty acid composition of rat alveolar macrophage (AM) and liver Kupffer and endothelial (K&E) cell phospholipids in vivo to the extent achieved during continuous feeding.
Rats were isocalorically fed through a gastrostomy catheter for 3 or 6 days with high-fat, low-carbohydrate diets that were enriched with either LA (diet A), EPA (diet B), or EPA + GLA (diet C). The rats were randomized by infusion modality, ie, continuous vs cyclic (14 hours feeding with 10 hours fasting daily) feeding. AM and K&E were isolated and phospholipid fatty acid profiles were determined by gas chromatography.
The dietary effects on AM and K&E cell phospholipid fatty acids for a given feeding period were not significantly influenced by the infusion modality. AM and K&E cells from rats receiving either diet B or diet C for 3 days had significantly lower AA and LA and higher EPA and dihomo-GLA (DHGLA), respectively, than rats given diet A regardless of the infusion modality. The mole % of EPA and DHGLA in K&E cells were higher after 6 vs 3 days of cyclic feeding with diet C. Using the eicosanoid precursor ratio (EPA + DHGLA/AA), the potential for generation of AA-derived eicosanoids was lower in rats given die B or C vs diet A regardless of infusion modality.
Given the rapid changes in lung and liver immune cell phospholipid fatty acids, short-term provision of EPA and GLA-enriched diets cyclically or continuously may prove clinically relevant for modulating the fatty acid composition and potential eicosanoid formation by these cells.
存在于肺和肝免疫细胞磷脂中的花生四烯酸（AA）是类花生酸的前体，可促进中性粒细胞边缘化，导致组织损伤和炎症。给予低亚油酸（LA）且含有鱼油中二十碳五烯酸（EPA）和琉璃苣油中γ-亚麻酸（GLA）的新型肠内制剂可取代AA，并促进具有降低炎症潜能的类花生酸的细胞形成。本研究旨在确定以循环方式短期提供含GLA、EPA或两者的肠内饮食是否能在体内调节大鼠肺泡巨噬细胞（AM）以及肝库普弗细胞和内皮细胞（K&E）磷脂的脂肪酸组成，达到持续喂养期间所实现的程度。
通过胃造口导管给大鼠等热量喂食3天或6天，喂食高脂肪、低碳水化合物饮食，这些饮食分别富含LA（饮食A）、EPA（饮食B）或EPA + GLA（饮食C）。大鼠按输注方式随机分组，即连续输注与循环输注（每天14小时喂食，10小时禁食）。分离出AM和K&E细胞，通过气相色谱法测定磷脂脂肪酸谱。
对于给定的喂养期，饮食对AM和K&E细胞磷脂脂肪酸的影响不受输注方式的显著影响。无论输注方式如何，接受饮食B或饮食C 3天的大鼠的AM和K&E细胞中AA和LA含量分别显著低于给予饮食A的大鼠，而EPA和二高γ-亚麻酸（DHGLA）含量更高。用饮食C循环喂养6天与3天后，K&E细胞中EPA和DHGLA的摩尔百分比更高。使用类花生酸前体比率（EPA + DHGLA/AA），无论输注方式如何，给予饮食B或C的大鼠中源自AA的类花生酸的生成潜力低于给予饮食A的大鼠。
鉴于肺和肝免疫细胞磷脂脂肪酸的快速变化，短期循环或持续提供富含EPA和GLA的饮食可能在临床上对于调节这些细胞的脂肪酸组成和潜在类花生酸形成具有相关性。
