Meijer G W, Beynen A C, Lovati M R, Manzoni C, Van Zutphen L F, Sirtori C R
Department of Laboratory Animal Science, University of Utrecht, The Netherlands.
J Nutr. 1992 Apr;122(4):931-9. doi: 10.1093/jn/122.4.931.
In two inbred strains of rabbits with high or low response of serum cholesterol to dietary cholesterol, binding of rabbit beta-VLDL to hepatic membrane preparations was determined. The objective was to test the hypothesis that after cholesterol feeding, hyperresponders show a more dramatic reduction in hepatic apolipoprotein (apo) B/E receptors, which may explain the development of the high degree of cholesterolemia in these animals. The number of hepatic high affinity receptors for beta-VLDL in hyperresponders fed a diet without added cholesterol was, on average, 20% lower than that in hyporesponders. After the addition of increasing amounts of cholesterol to the diet, liver cholesterol concentrations were elevated to a greater extent in hyper- than in hyporesponsive rabbits. Liver free cholesterol concentrations were negatively associated with maximal binding of beta-VLDL to liver membranes. With increasing liver free cholesterol concentrations, maximal binding was less effectively depressed in hyper- than hyporesponders. We conclude that in the inbred strains of rabbits, hyperresponsiveness to dietary cholesterol is not caused by enhanced depression of hepatic apo B/E receptors.
在对膳食胆固醇血清胆固醇反应高或低的两个近交系兔子中，测定了兔β-VLDL与肝膜制剂的结合。目的是检验以下假设：喂食胆固醇后，高反应者肝载脂蛋白（apo）B/E受体的减少更为显著，这可能解释了这些动物高度高胆固醇血症的发生。喂食无添加胆固醇饮食的高反应者中，肝β-VLDL高亲和力受体的数量平均比低反应者低20%。在饮食中添加越来越多的胆固醇后，高反应性兔子的肝脏胆固醇浓度升高幅度大于低反应性兔子。肝脏游离胆固醇浓度与β-VLDL与肝膜的最大结合呈负相关。随着肝脏游离胆固醇浓度的增加，高反应者的最大结合受到的抑制不如低反应者有效。我们得出结论，在近交系兔子中，对膳食胆固醇的高反应性不是由肝apo B/E受体的抑制增强引起的。
