Meijer G W, Stalenhoef A F, Demacker P N, Mol M J, Van Zutphen L F, Beynen A C
Department of Laboratory Animal Science, University of Utrecht, The Netherlands.
Lipids. 1992 Jun;27(6):474-7. doi: 10.1007/BF02536392.
In two inbred strains of rabbit with high or low response of plasma cholesterol to dietary cholesterol, low density lipoprotein (LDL) apolipoprotein (apoLDL) kinetics were determined with the use of a heterologous tracer isolated from a Watanabe heritable hyperlipidemic (WHHL) rabbit. On a diet without added cholesterol, the total clearance of apoLDL (which equals apoLDL production) did not differ significantly between rabbits of both strains. After the feeding of a diet containing 0.1% cholesterol for six weeks, plasma LDL cholesterol, plasma apoLDL and liver cholesterol concentrations rose significantly in the hyperresponsive but not in the hyporesponsive rabbits. Cholesterol feeding depressed the total fractional catabolic rate (FCR) of apoLDL in the hyper- but not in the hyporesponsive rabbits; this was attributed to a decrease of receptor-dependent FCR while receptor-independent FCR was similar in the two strains. On the diet containing cholesterol, the receptor-mediated absolute catabolic rate (ACR) of apoLDL did not differ between hyper- and hyporesponsive rabbits but receptor-independent ACR of apoLDL was higher in hyperresponders. It is concluded that the higher plasma apoLDL levels in hyperresponsive rabbits fed the 0.1% cholesterol diet are caused by a higher production of apoLDL and not by a lower flux of apoLDL through the receptor-mediated pathway.
在对膳食胆固醇有高或低血浆胆固醇反应的两种近交系兔子中，使用从渡边遗传性高脂血症（WHHL）兔子分离的异源示踪剂测定了低密度脂蛋白（LDL）载脂蛋白（apoLDL）的动力学。在不添加胆固醇的饮食条件下，两种品系兔子的apoLDL总清除率（等于apoLDL生成率）没有显著差异。在喂食含0.1%胆固醇的饮食六周后，高反应性兔子的血浆LDL胆固醇、血浆apoLDL和肝脏胆固醇浓度显著升高，而低反应性兔子则没有。喂食胆固醇降低了高反应性兔子而非低反应性兔子的apoLDL总分数分解代谢率（FCR）；这归因于受体依赖性FCR的降低，而受体非依赖性FCR在两个品系中相似。在含胆固醇的饮食中，高反应性和低反应性兔子之间apoLDL的受体介导绝对分解代谢率（ACR）没有差异，但高反应性兔子中apoLDL的受体非依赖性ACR更高。得出的结论是，喂食0.1%胆固醇饮食的高反应性兔子中较高的血浆apoLDL水平是由apoLDL的较高生成引起的，而不是由apoLDL通过受体介导途径的较低通量引起的。
