VALIDATION OF A NEW METHOD FOR DETERMINATION OF FREE FATTY-ACID TURNOVER
VALIDATION OF A NEW METHOD FOR DETERMINATION OF FREE FATTY-ACID TURNOVER
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DOI：
10.1152/ajpendo.1987.252.3.e431
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发表时间：
1987-03-01
影响因子：
--
通讯作者：
JENSEN, MD
中科院分区：
文献类型：
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作者：
MILES, JM;ELLMAN, MG;JENSEN, MD
在稳态条件下或非稳态条件下，用于估计游离脂肪酸（FFA）出现率（Ra）的示踪剂方法的准确性以前尚未研究。在本研究中，内源性脂解（跟踪与14 C棕榈酸酯）被抑制在6只杂种狗与高碳水化合物餐实验前10小时，连同输注的葡萄糖，普萘洛尔，烟酸在实验期间。稳态和非稳态方程均用于测定油酸乳剂逐步输注前、输注期间和输注后的油酸酯Ra（[3H]油酸酯）。棕榈酸Ra在实验期间没有变化。稳态方程给出了油酸盐流入量的最佳估计。93%的已知油酸输液速率的整体，而错误的示踪剂估计流入时，获得非稳态方程。油酸的代谢清除率与血药浓度呈负相关（P < 0.01）。总之，当使用稳态方程时，即使在Ra突然和最近变化的条件下，也可以获得FFA流入的准确估计。相反，非稳态方程可能提供错误的流入估计。外源性输注油酸时代谢清除率降低表明FFA转运可能遵循二级动力学。
The accuracy of tracer methods for estimating free fatty acid (FFA) rate of appearance (Ra), either under steady-state conditions or under non-steady conditions, has not been previously investigated. In the present study, endogenous lipolysis (traced with 14C palmitate) was suppressed in six mongrel dogs with a high-carbohydrate meal 10 h before the experiment, together with infusions of glucose, propranolol, and nicotinic acid during the experimental period. Both steady-state and non-steady-state equations were used to determine oleate Ra ([3H]oleate) before, during, and after a stepwise infusion of an oleic acid emulsion. Palmitate Ra did not change during the experiment. Steady-state equations gave the best estimates of oleate inflow .apprx. 93% of the known oleate infusion rate overall, while errors in tracer estimates of inflow were obtained when non-steady-state equations were used. The metabolic clearance rate of oleate was inversely related to plasma concentration (P < 0.01). In conclusion, accurate estimates of FFA inflow were obtained when steady-state equations were used, even under conditions of abrupt and recent changes in Ra. Non-steady-state equations, in contrast, may provide erroneous estimates of inflow. The decrease in metabolic clearance rate during exogenous infusion of oleate suggests that FFA transport may follow second-order kinetics.