Al-Shayji Iqbal A R, Gill Jason M R, Cooney Josephine, Siddiqui Samira, Caslake Muriel J
Department of Vascular Biochemistry, University of Glasgow, Glasgow, United Kingdom.
J Lipid Res. 2007 Sep;48(9):2086-95. doi: 10.1194/jlr.D600044-JLR200. Epub 2007 Jun 4.
Isotopic tracer methods of determining triglyceride-rich lipoprotein (TRL) kinetics are costly, time-consuming, and labor-intensive. This study aimed to develop a simpler and cost-effective method of obtaining TRL kinetic data, based on the fact that chylomicrons compete with large VLDL (VLDL(1); S(f) = 60-400) for the same catalytic pathway. Ten healthy subjects [seven men; fasting triglyceride (TG), 44.3-407.6 mg/dl; body mass index, 21-35 kg/m(2)] were given an intravenous infusion of a chylomicron-like TG emulsion (Intralipid; 0.1 g/kg bolus followed by 0.1 g/kg/h infusion) for 75-120 min to prevent the clearance of VLDL(1) by lipoprotein lipase. Multiple blood samples were taken during and after infusion for separation of Intralipid, VLDL(1), and VLDL(2) by ultracentrifugation. VLDL(1)-apolipoprotein B (apoB) and TG production rates were calculated from their linear increases in the VLDL(1) fraction during the infusion. Intralipid-TG clearance rate was determined from its exponential decay after infusion. The production rates of VLDL(1)-apoB and VLDL(1)-TG were (mean +/- SEM) 25.4 +/- 3.9 and 1,076.7 +/- 224.7 mg/h, respectively, and the Intralipid-TG clearance rate was 66.9 +/- 11.7 pools/day. Kinetic data obtained from this method agree with values obtained from stable isotope methods and show the expected relationships with indices of body fatness and insulin resistance (all P < 0.05). The protocol is relatively quick, inexpensive, and transferable to nonspecialist laboratories.
测定富含甘油三酯脂蛋白（TRL）动力学的同位素示踪方法成本高、耗时且劳动强度大。本研究旨在基于乳糜微粒与大颗粒极低密度脂蛋白（VLDL(1)；S(f)=60 - 400）竞争相同催化途径这一事实，开发一种更简单且经济高效的获取TRL动力学数据的方法。对10名健康受试者[7名男性；空腹甘油三酯（TG），44.3 - 407.6mg/dl；体重指数，21 - 35kg/m²]静脉输注一种类似乳糜微粒的TG乳剂（英脱利匹特；0.1g/kg推注，随后以0.1g/kg/h输注）75 - 120分钟，以防止脂蛋白脂肪酶清除VLDL(1)。在输注期间和之后采集多份血样，通过超速离心分离英脱利匹特、VLDL(1)和VLDL(2)。根据输注期间VLDL(1)组分中VLDL(1) - 载脂蛋白B（apoB）和TG的线性增加计算其生成速率。英脱利匹特 - TG清除率根据输注后其指数衰减来确定。VLDL(1) - apoB和VLDL(1) - TG的生成速率分别为（均值±标准误）25.4±3.9和1076.7±224.7mg/h，英脱利匹特 - TG清除率为66.9±11.7池/天。通过该方法获得的动力学数据与通过稳定同位素方法获得的值一致，并显示出与体脂和胰岛素抵抗指标的预期关系（所有P<0.05）。该方案相对快速、廉价且可应用于非专业实验室。
