Lei K Y, Rosenstein F, Shi F, Hassel C A, Carr T P, Zhang J
Department of Nutrition and Food Science, University of Arizona, Tucson 85721.
Proc Soc Exp Biol Med. 1988 Jul;188(3):335-41. doi: 10.3181/00379727-188-42743.
In view of the importance of membrane fluidity on cell functions, the influence of phospholipid acyl groups on membrane fluidity, and the changes in lipid metabolism induced by copper (Cu) deficiency, this study was designed to examine the influence of dietary Cu on the lipid composition and fluidity of liver plasma membranes. Male Sprague-Dawley rats were divided into two dietary treatments, namely Cu deficient and Cu adequate. After 8 weeks of treatment, liver plasma membranes were isolated by sucrose density gradient centrifugation. The lipid fluidity of plasma membranes, as assessed by the intramolecular eximer fluorescence of 1,3-di(1-pyrenyl) propane, was significantly depressed by Cu deficiency. In addition, Cu deficiency significantly reduced the content of arachidonic and palmitoleic acids but increased the docosatetraenoic and docosahexaenoic acids of membrane phospholipids. This alteration in unsaturated phospholipid fatty acid composition, especially the large reduction in arachidonic acid, may have contributed to the depressed membrane fluidity. Furthermore, Cu deficiency also markedly altered the fatty acid composition of the triacylglycerols associated with the plasma membranes. Thus, the lipid composition and fluidity of liver plasma membranes are responsive to the animal's Cu status.
鉴于膜流动性对细胞功能的重要性、磷脂酰基对膜流动性的影响以及铜（Cu）缺乏引起的脂质代谢变化，本研究旨在探讨日粮铜对肝质膜脂质组成和流动性的影响。将雄性Sprague-Dawley大鼠分为两种日粮处理组，即缺铜组和铜充足组。处理8周后，通过蔗糖密度梯度离心法分离肝质膜。通过1,3-二（1-芘基）丙烷的分子内准分子荧光评估，缺铜显著降低了质膜的脂质流动性。此外，缺铜显著降低了花生四烯酸和棕榈油酸的含量，但增加了膜磷脂中二十二碳四烯酸和二十二碳六烯酸的含量。不饱和磷脂脂肪酸组成的这种变化，尤其是花生四烯酸的大幅减少，可能导致了膜流动性的降低。此外，缺铜还显著改变了与质膜相关的三酰甘油的脂肪酸组成。因此，肝质膜的脂质组成和流动性对动物的铜状态有反应。
