出版社：American Society for Biochemistry and Molecular Biology
摘要：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 methodof obtaining TRL kinetic data, based on the fact that chylomicronscompete with large VLDL (VLDL1; Sf = 60–400) for the samecatalytic pathway. Ten healthy subjects [seven men; fastingtriglyceride (TG), 44.3–407.6 mg/dl; body mass index,21–35 kg/m2] were given an intravenous infusion of a chylomicron-likeTG emulsion (Intralipid; 0.1 g/kg bolus followed by 0.1 g/kg/hinfusion) for 75–120 min to prevent the clearance of VLDL1by lipoprotein lipase. Multiple blood samples were taken duringand after infusion for separation of Intralipid, VLDL1, andVLDL2 by ultracentrifugation. VLDL1-apolipoprotein B (apoB)and TG production rates were calculated from their linear increasesin the VLDL1 fraction during the infusion. Intralipid-TG clearancerate was determined from its exponential decay after infusion.The production rates of VLDL1-apoB and VLDL1-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 ± 11.7pools/day. Kinetic data obtained from this method agree withvalues obtained from stable isotope methods and show the expectedrelationships with indices of body fatness and insulin resistance(all P < 0.05). The protocol is relatively quick, inexpensive,and transferable to nonspecialist laboratories.Supplementary key words Intralipid • triglyceride • apolipoprotein B • production • clearance
Abbreviations: apoB, apolipoprotein B; BMI, body mass index; FCR, fractional catabolic rate; FSR, fractional synthetic rate; HOMAIR, homeostasis model assessment insulin resistance; Sf, Svedberg flotation rate; TG, triglyceride; TRL, triglyceride-rich lipoprotein
