Hassel C A, Lei K Y, Carr T P, Marchello J A
Department of Nutrition and Food Science, University of Arizona, Tucson 85721.
Metabolism. 1987 Nov;36(11):1054-62. doi: 10.1016/0026-0495(87)90025-4.
Twenty-four male weanling Sprague-Dawley rats were randomly and equally divided into two dietary treatments, copper-deficient and adequate (0.7 mg and 8.0 mg Cu/kg diet, respectively). Deionized water and diet were provided ad libitum. After 8 weeks, rats were exsanguinated, membranes prepared from livers, and plasma high density lipoproteins (HDL) isolated by ultracentrifugation and agarose column chromatography. Heparin-sepharose affinity chromatography was used to isolate subfractions of HDL devoid of apolipoprotein E (apo E-free HDL). The apo E-free HDL derived from rats of each dietary treatment were iodinated and bound to liver membranes prepared from rats of both treatment groups. Total binding data, specific binding data, and computer derived estimates of maximum equilibrium binding (Bmax) indicate less binding was observed when lipoproteins and membranes from copper-deficient animals were used in the binding assay compared to controls. In addition, a 2 X 2 factorial analysis of binding parameters derived from all experiments demonstrated a significant lipoprotein effect, indicating the reduction in binding may be associated with apo E-free HDL obtained from copper-deficient rats. The present findings suggest a reduction in binding of apo E-free HDL to their binding sites may contribute to the hypercholesterolemia and hyperlipoproteinemia observed in copper deficiency.
24只雄性断乳斯普拉格-道利大鼠被随机等分为两种饮食处理组，即缺铜组和正常铜组（分别为每千克饮食含0.7毫克和8.0毫克铜）。自由提供去离子水和饮食。8周后，将大鼠放血，从肝脏制备细胞膜，并通过超速离心和琼脂糖柱色谱法分离血浆高密度脂蛋白（HDL）。使用肝素-琼脂糖亲和色谱法分离不含载脂蛋白E的HDL亚组分（无载脂蛋白E的HDL）。将每种饮食处理组大鼠来源的无载脂蛋白E的HDL碘化，并与两个处理组大鼠制备的肝细胞膜结合。总结合数据、特异性结合数据以及通过计算机得出的最大平衡结合量（Bmax）估计值表明，与对照组相比，在结合试验中使用缺铜动物的脂蛋白和细胞膜时，观察到的结合较少。此外，对所有实验得出的结合参数进行的2×2析因分析显示出脂蛋白有显著影响，表明结合减少可能与从缺铜大鼠获得的无载脂蛋白E的HDL有关。目前的研究结果表明，无载脂蛋白E的HDL与其结合位点的结合减少可能是导致缺铜时出现高胆固醇血症和高脂蛋白血症的原因。
