DIETARY CHOLESTEROL EFFECTS ON PLASMA LIPOPROTEINS

研究表明，膳食中的胆固醇和饱和脂肪含量增加 与血浆胆固醇水平升高有关 (尤其是低密度脂蛋白)和血管疾病。这个 本研究的目的是确定饮食对健康的影响 胆固醇，结合饱和摄入量的低或高 脂肪，对人体血浆胆固醇代谢的影响。这项研究将 特别关注血浆中的生化反应 促进外周细胞胆固醇回流到肝脏 (反向胆固醇运输)。在人类受试者和 低等灵长类动物(狒狒)发现这种运输方式非常剧烈。 在餐后脂血症中受到刺激。初步数据现在表明 这种刺激被慢性(6-8周)明显抑制 增加饮食中胆固醇的摄入量。年轻和年长的男性 志愿者将食用不同于传统饮食形式的 胆固醇和饱和脂肪含量，在一般情况下制备 临床研究中心。的血浆质量和活性 胆固醇反向运输途径的组成部分将是 在空腹血浆中测定，在餐后血脂中测定 这些受试者适应了每种饮食。这些测量结果将 不仅包括在水平和组成上制作的那些 脂蛋白本身，还有酶和其他催化剂 促进脂蛋白的修饰和清除 胆固醇。将获得的数据将提供详细的新 膳食胆固醇对血浆影响的文献记载 脂蛋白代谢，特别是表明饮食是否 胆固醇抑制外周细胞胆固醇向外周血 受试者的肝脏。

Increased dietary cholesterol and saturated fat have been shown to be related to increased levels of plasma cholesterol (particularly in low density lipoproteins) and vascular disease. The purpose of this study is to determine the effects of dietary cholesterol, in combination with low or high intake of saturated fat, on human plasma cholesterol metabolism. The study will focus particularly on the biochemical reactions in plasma promoting the return of peripheral cell cholesterol to the liver (reverse cholesterol transport). Studies in human subjects and lower primates (babboons) have found such transport to be acutely stimulated in postprandial lipemia. Preliminary data now suggests that this stimulation is markedly inhibited by chronic (6-8 week) increased intake of dietary cholesterol. Young and older male volunteers will consume diets of traditional format differing in cholesterol and saturated fat content, prepared in the General Clinical Research Center. The plasma mass and activities of components of the reverse cholesterol transport pathway will be determined in fasting plasma, and during postprandial lipemia, in these subjects adapted to each diet. These measurements will include not only those made on the levels and compositions of the lipoproteins themselves, but also the enzyme and other catalysts promoting the modification and clearance of lipoprotein cholesterol. The data to be obtained will provide detailed new documentation of the effects of dietary cholesterol on plasma lipoprotein metabolism and in particular, indicate whether dietary cholesterol inhibits the return of peripheral cell cholesterol to the liver in human subjects.