DESATURATION OF ESSENTIAL FATTY ACIDS USING STABLE ISOTOPE GC-MS

必需脂肪酸(EFA)、亚油酸(18：2N6)和亚麻酸 (18：3n3)，脱饱和并拉长为花生四烯酸(20：4n6)和 二十二碳六烯酸(22：6n3)。一种稳定的同位素气体 色质联用(GC-MS)方法正被用于检测 活体内的这些过程。对小鼠、大鼠、猫、恒河猴和 人类认为所有的哺乳动物都有伸长和减饱和。 而且他们的产品可以在血液中进行监测。在……里面 一般来说，乙醇的消费会降低人体内20：4n6和22：6n3的水平。 动物的血细胞和肝脏。我们已经证明了这些机制 体内必需脂肪酸水平紊乱的根本原因是 组织的部分原因是伸长/去饱和度的抑制 通过酒精摄取18碳必需脂肪酸。一项关于猫科动物的研究 六个月的饮酒显示出20：4n6和22：6n3的显著减少 将肝脏和血液与对照组进行比较。在大脑和视网膜中 22：6n3水平下降，20：4n6水平保持不变。在……里面 一项恒河猴研究，饮食中含有少量但充足的 必需脂肪酸和最低水平的抗氧化剂，12个月 酒精暴露导致肝脏中22L6n3水平急剧下降 和血浆。血浆中20：4N6的水平也下降了约 50%。酒精暴露对脑和视网膜中22：6N3水平的影响 猴子的体重比以食物喂养的动物低得多。有人建议， 因此，长期接触酒精会导致全民教育不足 这会导致神经系统中22：6n3的含量较低。一个 在猫科动物中的相关研究表明，神经长的维持 链状多不饱和化合物是视网膜正常发育所必需的 功能。

The essential fatty acids (EFA), linoleate (18:2n6) and linolenate (18:3n3), are desaturated and elongated to arachidonate (20:4n6) and docosahexaenoate (22:6n3), respectively. A stable isotope gas chromatography-mass spectrometry (GC-MS) method is being used to examine these processes in vivo. Studies in mice, rats, cats, rhesus monkeys and humans have suggested that all mammals have elongation and desaturation capability and that their products may be monitored in the blood. In general, ethanol consumption lowers the levels of 20:4n6 and 22:6n3 in the blood cells and livers of animals. We have shown that the mechanisms underlying the disruption of the essential fatty acid levels in these tissues are, in part, due to the inhibition of the elongation/desaturation of 18-carbon essential fatty acids by alcohol. A study in felines given alcohol for six months showed marked reductions of 20:4n6 and 22:6n3 in the liver and blood compared to controls. In the brain and retina the levels of 22:6n3 decreased, however, 20:4n6 levels remained unchanged. In a rhesus monkey study where the diet contained low but adequate amounts of essential fatty acids and minimal levels of antioxidants, 12 months of alcohol exposure led to sharp declines in the level of 22L6n3 in the liver and plasma. The level of 20:4n6 in the plasma also decreased by about 50%. The levels of 22:6n3 in the brain and retina of an alcohol exposed monkey were much lower relative to chow-fed animals. It is suggested, therefore, that chronic alcohol exposure causes an EFA deficiency in animals which leads to lower amounts of 22:6n3 in the nervous system. A related study in felines indicated that the maintenance of neural long chain polyunsaturates is necessary for the proper development of retinal function.