Parrish C C, Myher J J, Kuksis A, Angel A
Department of Medicine, University of Toronto, Canada.
Biochim Biophys Acta. 1997 Jan 31;1323(2):253-62. doi: 10.1016/s0005-2736(96)00192-7.
We have determined the changes in the lipid structure of the adipocyte plasma membranes of rats receiving lard or fish oil in their diet. For this purpose, mature Wistar rats were fed 20% (w/w) lard or fish oil diets for 22 days, when the plasma membranes of the epididymal and perirenal adipocytes were prepared. Detailed analysis of the membrane lipids by chromatographic methods showed that dietary fat exerted a major effect on the lipid class and molecular species composition of the phospholipids. As a result of fish oil feeding, significant increases in the 20:5(n-3), 22:5(n-3) and 22:6(n-3) were detected in all glycerophospholipid classes, while the 18:1(n-9) and 18:2(n-6) and to a lesser extent 20:4(n-6) decreased. Incorporation of n-3 fatty acids increased the phosphatidylcholine/sphingomyelin ratio without changing the total phospholipid or free cholesterol content of the membrane. Fish oil feeding also caused a marked increase in the proportion of 24:1 in sphingomyelins, which occurred mainly at the expense of 18:0 and 24:0. New n-3 fatty acid-containing species appeared in the choline and ethanolamine glycerophospholipids, when compared to membrane lipids from lard-fed rats. Membranes from fish oil fed rats also had moderately higher levels of ether lipids. Few differences were seen between the membranes of the epididymal and perirenal adipocytes. It is concluded that dietary fish oils modify the lipid structure of rat adipocyte plasma membranes by increasing the ratio of phosphatidylcholine to sphingomyelin and by increasing the proportion of molecular species with polyunsaturated fatty acids, which would be anticipated to increase the fluidity of the lipid bilayer of adipocyte plasma membranes.
我们已经确定了饮食中摄入猪油或鱼油的大鼠脂肪细胞质膜脂质结构的变化。为此，将成熟的Wistar大鼠喂食20%（w/w）的猪油或鱼油饮食22天，然后制备附睾和肾周脂肪细胞的质膜。通过色谱方法对膜脂质进行的详细分析表明，饮食脂肪对磷脂的脂质类别和分子种类组成有主要影响。喂食鱼油的结果是，在所有甘油磷脂类别中均检测到20:5(n-3)、22:5(n-3)和22:6(n-3)显著增加，而18:1(n-9)、18:2(n-6)以及程度较轻的20:4(n-6)减少。n-3脂肪酸的掺入增加了磷脂酰胆碱/鞘磷脂的比例，而没有改变膜的总磷脂或游离胆固醇含量。喂食鱼油还导致鞘磷脂中24:1的比例显著增加，这主要是以18:0和24:0为代价的。与喂食猪油的大鼠的膜脂质相比，胆碱和乙醇胺甘油磷脂中出现了新的含n-3脂肪酸的种类。喂食鱼油的大鼠的膜中醚脂质水平也适度较高。附睾和肾周脂肪细胞质膜之间几乎没有差异。结论是，饮食中的鱼油通过增加磷脂酰胆碱与鞘磷脂的比例以及增加多不饱和脂肪酸分子种类的比例来改变大鼠脂肪细胞质膜的脂质结构，这预计会增加脂肪细胞质膜脂质双层的流动性。
