Portman O W, Illingworth D R, Alexander M
Biochim Biophys Acta. 1975 Jul 22;398(1):55-71. doi: 10.1016/0005-2760(75)90169-1.
We studied the metabolism of different classes of lipoprotein in squirrel monkeys and rabbits. Lipoproteins were labeled in vivo in donor animals with (3H)leucine and (3H)cholesterol. The rate of disappearance from plasma of recipient squirrel monkeys of the protein moiety of the very low density lipoproteins was rapid, that of high density lipoproteins slow, and the rate for low density lipoproteins was intermediate. The fractional turnover of the apoprotein of low density lipoproteins was slightly reduced in hyperlipidemic monkeys, but the absolute rates of synthesis and catabolism were increased. Hyperdipidemia in rabbits resulted in a dramatic reduction in the fractional catabolic rate of low density lipoprotein apoprotein. Hyperlipidemia in the donors of biosynthetic low density lipoproteins also influenced the rates of catabolism in rabbits. We showed the cycloheximide that although there was recycling of (3H)leucine into other proteins, the reutilization of leucine from low density lipoproteins for nascent low density lipoproteins was not significant. In most tissues the ratio of cholesterol:protein radioactivity was much greater than that for plasma 24 h after administration of labeled low density lipoproteins, but the ratios for aortic intima plus inner media and for plasma low density lipoproteins were similar. The presence of atherosclerosis resulted in a large increase in the apparent uptake of low density lipoproteins by the aortas of rabbits and monkeys.
我们研究了松鼠猴和兔子体内不同种类脂蛋白的代谢情况。在供体动物体内，用（3H）亮氨酸和（3H）胆固醇对脂蛋白进行标记。极低密度脂蛋白蛋白质部分在受体松鼠猴血浆中的消失速率很快，高密度脂蛋白的消失速率很慢，低密度脂蛋白的消失速率则介于两者之间。高脂血症猴子中低密度脂蛋白载脂蛋白的分数周转率略有降低，但合成和分解代谢的绝对速率增加。兔子的高脂血症导致低密度脂蛋白载脂蛋白的分数分解代谢率显著降低。生物合成低密度脂蛋白供体的高脂血症也影响了兔子的分解代谢速率。我们发现，尽管（3H）亮氨酸会再循环到其他蛋白质中，但低密度脂蛋白中的亮氨酸再用于新生低密度脂蛋白的情况并不显著。在大多数组织中，给予标记的低密度脂蛋白24小时后，胆固醇与蛋白质的放射性比值远高于血浆中的该比值，但主动脉内膜加中膜与血浆低密度脂蛋白的该比值相似。动脉粥样硬化的存在导致兔子和猴子主动脉对低密度脂蛋白的表观摄取大幅增加。
