短期或长期饮食暴露后，α-亚麻酸与二十二碳六烯酸供应对脂肪酸在大鼠心脏亚细胞膜中分布的影响。
Effects of alpha-linolenic acid vs. docosahexaenoic acid supply on the distribution of fatty acids among the rat cardiac subcellular membranes after a short- or long-term dietary exposure.
机构信息
Institut National de la Recherche Agronomique (INRA)-Université Paris-Sud 11, Unité Mixte de Recherche 1154, Lipides Membranaires et Régulation Fonctionnelle du Coeur et des Vaisseaux, Institut Fédératif de Recherche 141, Faculté de Pharmacie, Châtenay-Malabry, F-92296, France.
出版信息
Nutr Metab (Lond). 2009 Mar 25;6:14. doi: 10.1186/1743-7075-6-14.
BACKGROUND
Previous work showed that the functional cardiac effect of dietary alpha-linolenic acid (ALA) in rats requires a long feeding period (6 months), although a docosahexaenoic (DHA) acid-supply affects cardiac adrenergic response after 2 months. However, the total cardiac membrane n-3 polyunsaturated fatty acid (PUFA) composition remained unchanged after 2 months. This delay could be due to a specific reorganization of the different subcellular membrane PUFA profiles. This study was designed to investigate the evolution between 2 and 6 months of diet duration of the fatty acid profile in sarcolemmal (SL), mitochondrial (MI), nuclear (NU) and sarcoplasmic reticulum (SR) membrane fractions.
METHODS
Male Wistar rats were randomly assigned to 3 dietary groups (n = 10/diet/period), either n-3 PUFA-free diet (CTL), or ALA or DHA-rich diets. After 2 or 6 months, the subcellular cardiac membrane fractions were separated by differential centrifugations and sucrose gradients. Each membrane profile was analysed by gas chromatography (GC) after lipid extraction.
RESULTS
As expected the n-3 PUFA-rich diets incorporated n-3 PUFA instead of n-6 PUFA in all the subcellular fractions, which also exhibited individual specificities. The diet duration increased SFA and decreased PUFA in SL, whereas NU remained constant. The SR and MI enriched in n-3 PUFA exhibited a decreased DHA level with ageing in the DHA and CTL groups. Conversely, the n-3 PUFA level remained unchanged in the ALA group, due to a significant increase in docosapentaenoic acid (DPA). N-3 PUFA rich diets lead to a better PUFA profile in all the fractions and significantly prevent the profile modifications induced by ageing.
CONCLUSION
With the ALA diet the n-3 PUFA content, particularly in SR and SL kept increasing between 2 and 6 months, which may partly account for the delay to achieve the modification of adrenergic response.
背景
之前的研究表明，膳食 α-亚麻酸（ALA）对大鼠心脏的功能作用需要较长的喂养期（6 个月），尽管二十二碳六烯酸（DHA）的供应会影响心脏肾上腺素反应，但仅需 2 个月。然而，在 2 个月后，心肌总膜 n-3 多不饱和脂肪酸（PUFA）组成保持不变。这种延迟可能是由于不同亚细胞膜 PUFA 谱的特定重组。本研究旨在探讨在 2 至 6 个月的饮食期间，骨骼肌膜（SL）、线粒体（MI）、核（NU）和肌浆网（SR）膜部分脂肪酸谱的演变。
方法
雄性 Wistar 大鼠随机分为 3 个饮食组（n = 10/饮食/周期），即 n-3PUFA 缺乏饮食（CTL）、ALA 或 DHA 丰富饮食。2 或 6 个月后，通过差速离心和蔗糖梯度分离亚细胞心脏膜部分。脂质提取后，用气相色谱（GC）分析每种膜谱。
结果
如预期的那样，n-3 PUFA 丰富的饮食将 n-3 PUFA 替代了所有亚细胞部分中的 n-6 PUFA，同时也表现出了个体特异性。随着饮食时间的延长，SL 中的 SFA 增加，PUFA 减少，而 NU 保持不变。富含 n-3 PUFA 的 SR 和 MI 随着年龄的增长，DHA 水平在 DHA 和 CTL 组中下降。相反，ALA 组中的 n-3 PUFA 水平保持不变，这是由于二十二碳五烯酸（DPA）显著增加所致。富含 n-3 PUFA 的饮食可改善所有部分的 PUFA 谱，并显著防止老化引起的谱改变。
结论
用 ALA 饮食，SR 和 SL 中的 n-3 PUFA 含量在 2 至 6 个月之间持续增加，这可能部分解释了实现肾上腺素反应改变的延迟。
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