致动脉粥样化饮食对猪低密度脂蛋白结构的影响。

Pownall H J, Jackson R L, Roth R I, Gotto A M, Patsch J R, Kummerow F A

J Lipid Res. 1980 Nov;21(8):1108-15.

Five groups of three swine each were fed a basal diet supplemented with 15% tallow and either 0.0, 1.0, 1.5, 2.0%, or 2.5% cholesterol. The animals were studied over a period of 9 weeks to observe changes in plasma lipids and low density lipoproteins (LDL). At the end of the study period, LDL was analyzed by rate zonal ultracentrifugation, characterized chemically, and examined by differential scanning calorimetry. Within 3 weeks of initiation of the cholesterol-supplemented diets, there was an increase in the plasma levels of cholesterol and total LDL. LDL from swine fed the basal diet and the basal diet plus 1.0% cholesterol appeared in two LDL populations (LDL1 and LDL2) when analyzed by rate zonal ultracentrifugation. After diets containing 1.5, 2.0, and 2.5% dietary cholesterol, there was an increase in the mean flotation rate of total LDL which shifted to a lower density. LDL1 from the high cholesterol diets had a decreased triglyceride content when compared to those of the low cholesterol diets. When examined by differential scanning calorimetry, the LDL1 from the animals fed at least 1.5% cholesterol had phase transitions above body temperature, whereas the LDL from those fed 0 and 1.0% cholesterol had phase transitions below 37 degrees C. In contrast, the thermal behavior and fatty acid compositions of the extracted cholesteryl esters of the LDL obtained after the five different diets were not remarkably different. Since LDL triglyceride and cholesteryl esters are predicted to coexist in a common phase in the LDL core, the different thermal behavior of the LDL obtained after diets with different cholesterol contents is due to differences in triglyceride content which are a secondary effect of cholesterol-feeding. From these data we conclude that dietary cholesterol increases plasma LDL content, decreases LDL triglyceride content, and alters the particle structure. These changes in lipoprotein structure may contribute to the known development of atherosclerosis in cholesterol-fed swine.

将五组猪，每组三头，喂食添加了15%牛脂以及0.0%、1.0%、1.5%、2.0%或2.5%胆固醇的基础日粮。对这些动物进行为期9周的研究，以观察血浆脂质和低密度脂蛋白（LDL）的变化。在研究期结束时，通过速率区带超速离心法分析LDL，进行化学表征，并通过差示扫描量热法进行检测。在开始喂食添加胆固醇的日粮后的3周内，血浆胆固醇水平和总LDL水平有所升高。通过速率区带超速离心法分析时，喂食基础日粮以及基础日粮加1.0%胆固醇的猪的LDL出现两个LDL群体（LDL1和LDL2）。在日粮中含有1.5%、2.0%和2.5%膳食胆固醇后，总LDL的平均漂浮率增加，且向较低密度偏移。与低胆固醇日粮的LDL1相比，高胆固醇日粮的LDL1甘油三酯含量降低。通过差示扫描量热法检测时，喂食至少1.5%胆固醇的动物的LDL1在体温以上有相变，而喂食0%和1.0%胆固醇的动物的LDL在37摄氏度以下有相变。相比之下，在五种不同日粮后获得的LDL的提取胆固醇酯的热行为和脂肪酸组成没有显著差异。由于预计LDL甘油三酯和胆固醇酯在LDL核心中共存于一个共同相中，不同胆固醇含量日粮后获得的LDL的不同热行为是由于甘油三酯含量的差异，这是喂食胆固醇的次要效应。从这些数据我们得出结论，膳食胆固醇会增加血浆LDL含量，降低LDL甘油三酯含量，并改变颗粒结构。脂蛋白结构的这些变化可能有助于胆固醇喂养的猪中已知的动脉粥样硬化发展。