Korhonen T, Savolainen M J, Kesäniemi Y A
Department of Internal Medicine and Biocenter Oulu, University of Oulu, Finland.
Atherosclerosis. 1999 Sep;146(1):1-10. doi: 10.1016/s0021-9150(99)00106-9.
The fractional catabolic rate (FCR) for low density lipoprotein (LDL) apolipoprotein B (apo B) was studied to explore the variations in apo B as a possible cause of hypercholesterolemia. The FCR of radioiodine labelled autologous LDL and homologous LDL isolated from a normocholesterolemic subject were compared in forty-nine type II hypercholesterolemic males and females with the mean plasma concentration of total cholesterol of 7.78 mmol/l, LDL-cholesterol 5.41 mmol/l and triglycerides 2.09 mmol/l. In most patients the autologous LDL was catabolized at an equal rate and sometimes even faster than the homologous LDL. However, twelve out of forty-nine patients catabolized homologous LDL 0.8-19.3% faster than autologous LDL and several apo B polymorphisms were determined. No apo B-3500 or apo B-3531 mutations were detected. Patients with XbaI -/- (absence of cutting site) had lower total, IDL and LDL cholesterol and LDL apoB than the other genotypes. Patients with EcoRI +/+ (presence of cutting site) had higher total, VLDL and LDL cholesterol and slower FCR for autologous LDL, and their VLDL was richer in cholesterol than that of patients with the EcoRI +/-. The MspI and ins/del polymorphisms were not associated with variations in the measured parameters. The apo E 4 was associated with higher VLDL and IDL cholesterol, higher triglycerides and LDL apo B than E 3/3. Overall, the determined apo B polymorphisms were not related to the slow clearance of autologous LDL among the 12 patients, in whom autologous LDL was cleared at a slower rate than homologous LDL. In conclusion, hypercholesterolemia can be due to particle-related slow clearance of LDL in some patients. However, this is not a common cause of hypercholesterolemia.
研究了低密度脂蛋白（LDL）载脂蛋白B（apo B）的分解代谢率（FCR），以探讨apo B的变化作为高胆固醇血症可能病因的情况。在49例II型高胆固醇血症男性和女性中，比较了从一名血脂正常受试者分离的放射性碘标记自体LDL和同源LDL的FCR，这些患者的总胆固醇平均血浆浓度为7.78 mmol/l，LDL胆固醇为5.41 mmol/l，甘油三酯为2.09 mmol/l。在大多数患者中，自体LDL的分解代谢速率相同，有时甚至比同源LDL更快。然而，49例患者中有12例分解同源LDL的速度比自体LDL快0.8 - 19.3%，并确定了几种apo B多态性。未检测到apo B - 3500或apo B - 3531突变。XbaI -/-（无切割位点）的患者总胆固醇、中间密度脂蛋白（IDL）和LDL胆固醇以及LDL apoB低于其他基因型。EcoRI +/+（有切割位点）的患者总胆固醇、极低密度脂蛋白（VLDL）和LDL胆固醇较高，自体LDL的FCR较慢，且其VLDL中的胆固醇比EcoRI + / - 的患者更丰富。MspI和插入/缺失多态性与所测参数的变化无关。与E 3/3相比，apo E 4与更高的VLDL和IDL胆固醇、更高的甘油三酯以及LDL apo B相关。总体而言，在12例自体LDL清除速度比同源LDL慢的患者中，所确定的apo B多态性与自体LDL清除缓慢无关。总之，高胆固醇血症在某些患者中可能是由于与颗粒相关的LDL清除缓慢所致。然而，这并非高胆固醇血症的常见病因。
