Dobryniewski Jacek, Szajda Sławomir Dariusz, Waszkiewicz Napoleon, Zwierz Krzysztof
Oddział III Ogólnopsychiatryczny z Pododdziałem Psychogeriatrii SPPZOZ w Choroszczy.
Przegl Lek. 2007;64(2):91-9.
Essential Fatty Acids (EFA), are unsaturated fatty acids not produced by human being, but essential for proper functioning of the human body. To EFA-s belongs: linoleic acid (LA) (18:2,cis detla(9,12), omega6)--precursor o f gamma-linolenic acid (GLA), gamma-linolenic acid (GLA) (18:3,cisA6,9,12, )6) and alpha-linolenic acid (ALA)(18:3,cisdelta(9, 12, 15), omega3)--product of dehydrogenation of linoleic acid (LA). Most important EFA is gamma-linolenic acid (GLA)--18 carbons, one-carboxylic, non-branched fatty acid with 3 double cis-bonds (the last is situated by 6-th carbon from methylic end). The diet devoided of EFA leads to decreased growth, skin and kidney injury and infertility. Modern research of GLA and others EFA's is concerned mainly on therapeutic impact on the inflammatory process. The biogenic amines, cytokines, prostaglandins, tromboxanes and leukotrienes are the main inflammatory mediators. The last three are described with the common name eicosanoides (eico-twenty). Eicosanoides are synthesized from 20-carbon unsaturated fatty acids: dihomo-gamma-linoleic (DGLA) (20:3, cis delta(8,11,14), omega6), arachidonic acid (AA-20:4, cis delta(5,8,11,14), omega6), and eicosapentaenoic acid (EPA-20:5, cis delta(5,8,11,14,17, omega3). Derivatives of gamma and gamma-linolenic acids regulate the inflammatory process, through their opposed activity. PG2, leucotrien C4 and tromboxan A2 have the strongest proinflammatory action. Derivatives of alpha-linolenic acid 15-HETE and prostaglandin E1 (PGE1) have weak pro-inflammatory action, or even anti-inflammatory (PGE1), and additionally, they inhibit the transformation of arachidonic acid (AA) to leukotriens. delta6-desaturase (transformes linolenic acid into gamma-linolenic acid by making additional double bond) is the slowest step of the fatty acid metabolism. It's activity is impaired by many physiological and pathologic factors and leads to gamma-linolenic acid (GLA) deficiency. The gamma-linolenic acid supplementation in diet allows to omitt the inefficient delta6-desaturase system which has an effect in rising of dihomo-gamma-linolenic acid (DGLA), arachidonic acid (AA) and their derivatives. This article describes biology of essential fatty acids and particularly the role of gamma-linolenic acid.
必需脂肪酸（EFA）是人体自身不能产生但对人体正常功能至关重要的不饱和脂肪酸。属于必需脂肪酸的有：亚油酸（LA）（18:2，顺式Δ(9,12)，ω6）——γ-亚麻酸（GLA）的前体、γ-亚麻酸（GLA）（18:3，顺式Δ6,9,12，ω6）和α-亚麻酸（ALA）（18:3，顺式Δ(9, 12, 15)，ω3）——亚油酸（LA）脱氢产物。最重要的必需脂肪酸是γ-亚麻酸（GLA）——一种含18个碳的一元羧酸、无支链的脂肪酸，有3个顺式双键（最后一个双键位于甲基端的第6个碳原子处）。缺乏必需脂肪酸的饮食会导致生长减缓、皮肤和肾脏损伤以及不育。目前对γ-亚麻酸和其他必需脂肪酸的研究主要关注其对炎症过程的治疗作用。生物胺、细胞因子、前列腺素、血栓素和白三烯是主要的炎症介质。后三种物质统称为类二十烷酸（eico-二十）。类二十烷酸由20碳不饱和脂肪酸合成：二高-γ-亚麻酸（DGLA）（20:3，顺式Δ(8,11,14)，ω6）、花生四烯酸（AA - 20:4，顺式Δ(5,8,11,14)，ω6）和二十碳五烯酸（EPA - 20:5，顺式Δ(5,8,11,14,17)，ω3）。γ-亚麻酸和γ-亚麻酸的衍生物通过其相反的活性调节炎症过程。PG2、白三烯C4和血栓素A2具有最强的促炎作用。α-亚麻酸的衍生物15 - HETE和前列腺素E1（PGE1）具有较弱的促炎作用，甚至具有抗炎作用（PGE1），此外，它们还抑制花生四烯酸（AA）向白三烯的转化。δ6-去饱和酶（通过形成额外的双键将亚麻酸转化为γ-亚麻酸）是脂肪酸代谢中最慢的步骤。它的活性受到许多生理和病理因素的损害，导致γ-亚麻酸（GLA）缺乏。在饮食中补充γ-亚麻酸可以避开效率低下的δ6-去饱和酶系统，这会导致二高-γ-亚麻酸（DGLA）、花生四烯酸（AA）及其衍生物增加。本文描述了必需脂肪酸的生物学特性，特别是γ-亚麻酸的作用。
