多不饱和脂肪酸对模拟失重大鼠脂质代谢的影响

目的：研究添加以鱼油为来源的不同剂量的多不饱和脂肪酸（PUFA）对模拟失重大鼠血清红细胞膜微粘度、循环内皮细胞、以及血清总胆固醇、血清甘油三酯等脂质代谢的调节。方法：选用3周龄断乳雄性SD大鼠49只，采用最小体差法分为5组：Ⅰ组悬吊对照，饲喂含10%玉米油饲料；Ⅱ、Ⅲ、Ⅳ组悬吊实验组，分别饲喂含0.5%和3.0%鱼油的合成饲料；Ⅴ组地面正常对照组，饲喂含10%玉米油饲料。悬吊时间为30d。结果：血清红细胞膜微粘度Ⅱ、Ⅳ组与Ⅴ组无显著性差异，Ⅲ组红细胞膜流动性有了显著的增加。Ⅱ组较为明显的减轻了模拟失重对循环内皮细胞（CEC）的增加作用，血清总胆固醇（TC）的含量与鱼油的添加量呈负相关，而血清甘油三酯（TG）含量在各剂量组中无显著性差异。Ⅰ组相对Ⅴ组血清冠心病指数（LDL/HDL）有显著升高而各悬吊实验组中LDL/HDL分别比Ⅰ组降低13.9%、11.1%和31.4%。结论：在模拟失重条件下，补充PUFA会减少失重对脂质代谢的不利作用，从而对动脉粥样硬化及冠心病（CHD）的发生起到一定的预防作用。

Effects of Dietary n-3 Polyunsaturated Fatty Acid on Lipid Metabolism in Rats under Simulated Weightlessness

Objective. To study the effect of dietary n-3 polyunsaturated fatty acid (PUFA) on the lipid metabolism of tail-suspended rats. Method. 49 male Sprague-Dawley rats were divided into five groups: tail-suspension group I, fed with 10 wt % corn oil, tail-suspension groups II, III, IV were fed with three levels of fish oil (0.5, 1.5 or 3.0 wt %; low, middle and high level of fish oil, respectively). Group V fed with 10 wt % corn oil served as normal control. Result. Viscoelasticity of cell membrane in group III was significantly higher than that of group I (P<0.01); Vascular endothelial cells (VEC) was less in group II compared to group I; Serum total cholesterol (TC) and triglyceride (TG) , serum lipoprotein were lower in groups II, III, IV compared to group I, the higher fish oil content in diet, the lower serum lipid concentration in microgravity. Conclusion. Dietary n-3 PUFA do have distinguished effect on lipid metabolism and n-3 PUFA have certain effects on prevention of atherosclerotic disease and coronary heart disease in rats.