Effect of cholesterol feeding on the distribution of plasma lipoproteins and on the metabolism of apolipoprotein E in the rabbit.
Effect of cholesterol feeding on the distribution of plasma lipoproteins and on the metabolism of apolipoprotein E in the rabbit.
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发表时间：
1983
影响因子：
6.5
通讯作者：
R. Roth;J. Gaubatz;A. Gotto;J. Patsch
中科院分区：
文献类型：
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作者：
R. Roth;J. Gaubatz;A. Gotto;J. Patsch
研究了饲粮中胆固醇含量为1%的家兔的脂蛋白分布和载脂蛋白E代谢的变化。脂蛋白分布监测速率分区超离心，凝胶过滤层析和电泳技术。正常血脂兔血浆中含有VLDL、IDL、LDL和HDL。在1%胆固醇饮食1周内，d < 1.006 g/ml的物质显著升高，高密度脂蛋白（LDL和HDL）降至检测水平以下。胆固醇含量低于1.006 g/ml的材料富含胆固醇酯，缺乏甘油三酯，并含有sf20至大于400的颗粒。饮食正常化后，LDL和HDL在2-4周内重新出现，并降低至低于1.006 g/ml的物质。通过向家兔注射纯化的125i标记的apoE，并在示踪剂清除后研究apoE的代谢。正常血脂血症家兔的ApoE分数分解代谢率（FCR）为0.132 hr-1，半衰期（t1/2）为10.3 hr。高胆固醇血症家兔ApoE的FCR为0.055 hr-1， t1/2为49.5 hr。电免疫测定结果显示，对照组血浆ApoE浓度为19.5 mg/dl，高胆固醇血症兔血浆ApoE浓度为199 mg/dl。根据这些数据，计算出对照组和高胆固醇血症兔的绝对合成率分别为20.3 mg/kg / d和86.1 mg/kg / d。我们得出结论，胆固醇补充饮食导致血浆中载脂蛋白e的显著升高，这是由于蛋白质的过量产生。
Changes in lipoprotein distribution and in apolipoprotein E metabolism were studied in rabbits fed a diet containing 1% cholesterol. Lipoprotein distribution was monitored by rate zonal ultracentrifugation, gel filtration chromatography, and electrophoretic techniques. Normolipidemic rabbit plasma contained VLDL, IDL, LDL, and HDL. Within 1 week on the 1% cholesterol diet, the d less than 1.006 g/ml material was greatly elevated, and the lipoproteins of higher density (LDL and HDL) decreased below levels of detection. Cholesteremic d less than 1.006 g/ml material was cholesteryl ester-rich, triglyceride-poor, and contained particles of Sf 20 to greater than 400. Upon diet normalization, the LDL and HDL reappeared within 2-4 weeks accompanied by a decrease in the d less than 1.006 g/ml material. The metabolism of apoE was studied by injecting purified and 125I-labeled apoE into rabbits and following the clearance of the tracer. ApoE in the normolipemic rabbit demonstrated a fractional catabolic rate (FCR) of 0.132 hr-1 and a half-life (t1/2) of 10.3 hr. ApoE in the hypercholesterolemic rabbit demonstrated an FCR of 0.055 hr-1 and a t1/2 of 49.5 hr. ApoE concentrations in the plasma as estimated by electroimmunoassay were 19.5 mg/dl in the control rabbit and 199 mg/dl in the hypercholesterolemic rabbit. From these data, absolute synthetic rates of 20.3 mg/kg per day and 86.1 mg/kg per day were calculated for the control and the hypercholesterolemic rabbit, respectively. We conclude that the cholesterol-supplemented diet caused pronounced elevation of apoE in the plasma due to overproduction of the protein.