Iritani N, Mizoguchi H, Kitaya M
Lipids. 1987 Jan;22(1):45-50. doi: 10.1007/BF02534874.
Rats adapted to a corn oil or a fish oil diet were fed a fat-free diet, and changes in phospholipid polyunsaturated fatty acids (PUFA) in the inner and outer leaflets of liver microsomal membranes were followed for 18 wk. In rats previously adapted to a corn oil diet, arachidonic acid in phosphatidylcholine and phosphatidylethanolamine in the inner and outer leaflets did not decrease quickly; rather, linoleic acid decreased more than arachidonic acid for the first three weeks of feeding the fat-free diet. Even at 18 wk, 40-50% of the beginning arachidonic acid levels were still retained. In contrast, in rats previously adapted to a fish oil diet, the n-3 PUFA were quickly decreased by the fat-free diet to only 10-30% at 18 wk. Due to the appearance and increase of n-9 eicosatrienoic acid in the replacement of the n-3 and n-6 PUFA, total PUFA did not decrease in the inner and outer phosphatidylcholine in either group, but decreased somewhat in the phosphatidylethanolamine due to the insufficient increase of the n-9. On the other hand, the overall degrees of unsaturation in phosphatidylcholine fatty acids were always higher in the outer than in the inner leaflets and were not altered by feeding the fat-free diet even for 18 wk. Thus, the results appear to reveal the physiological importance of unsaturation ratio of fatty acids and the necessity of arachidonic acid in each membrane leaflet.
将适应玉米油或鱼油饮食的大鼠改为喂食无脂饮食，并跟踪肝微粒体膜内外小叶中磷脂多不饱和脂肪酸（PUFA）的变化，持续18周。在先前适应玉米油饮食的大鼠中，内外小叶中磷脂酰胆碱和磷脂酰乙醇胺中的花生四烯酸不会迅速减少；相反，在喂食无脂饮食的前三周，亚油酸的减少幅度大于花生四烯酸。即使在18周时，仍保留了初始花生四烯酸水平的40-50%。相比之下，在先前适应鱼油饮食的大鼠中，无脂饮食使n-3多不饱和脂肪酸迅速减少，在18周时仅降至10-30%。由于n-9二十碳三烯酸的出现和增加以取代n-3和n-6多不饱和脂肪酸，两组大鼠内外磷脂酰胆碱中的总多不饱和脂肪酸并未减少，但由于n-9增加不足，磷脂酰乙醇胺中的总多不饱和脂肪酸有所减少。另一方面，磷脂酰胆碱脂肪酸的总体不饱和度在外小叶中总是高于内小叶，并且即使喂食18周的无脂饮食也不会改变。因此，这些结果似乎揭示了脂肪酸不饱和度的生理重要性以及每个膜小叶中花生四烯酸的必要性。
